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Publisher: Elsevier   (Total: 3163 journals)

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Showing 1 - 200 of 3163 Journals sorted alphabetically
A Practical Logic of Cognitive Systems     Full-text available via subscription   (Followers: 9)
AASRI Procedia     Open Access   (Followers: 14)
Academic Pediatrics     Hybrid Journal   (Followers: 30, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 22, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 88, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 25, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 35, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 5)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 7)
Acta Astronautica     Hybrid Journal   (Followers: 394, SJR: 0.758, CiteScore: 2)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 27, SJR: 1.967, CiteScore: 7)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 2)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.18, CiteScore: 1)
Acta Haematologica Polonica     Free   (Followers: 1, SJR: 0.128, CiteScore: 0)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 244, SJR: 3.263, CiteScore: 6)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.504, CiteScore: 1)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.542, CiteScore: 1)
Acta Oecologica     Hybrid Journal   (Followers: 10, SJR: 0.834, CiteScore: 2)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.307, CiteScore: 0)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 1, SJR: 1.793, CiteScore: 6)
Acta Poética     Open Access   (Followers: 4, SJR: 0.101, CiteScore: 0)
Acta Psychologica     Hybrid Journal   (Followers: 27, SJR: 1.331, CiteScore: 2)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.052, CiteScore: 2)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 3, SJR: 0.374, CiteScore: 1)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 2)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.344, CiteScore: 1)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 1)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 6, SJR: 0.19, CiteScore: 0)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 6)
Acute Pain     Full-text available via subscription   (Followers: 15, SJR: 2.671, CiteScore: 5)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.53, CiteScore: 4)
Addictive Behaviors     Hybrid Journal   (Followers: 16, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 8, SJR: 0.755, CiteScore: 2)
Additive Manufacturing     Hybrid Journal   (Followers: 9, SJR: 2.611, CiteScore: 8)
Additives for Polymers     Full-text available via subscription   (Followers: 22)
Advanced Cement Based Materials     Full-text available via subscription   (Followers: 3, SJR: 0.732, CiteScore: 3)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 134, SJR: 4.09, CiteScore: 13)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.167, CiteScore: 4)
Advanced Powder Technology     Hybrid Journal   (Followers: 16, SJR: 0.694, CiteScore: 3)
Advances in Accounting     Hybrid Journal   (Followers: 8, SJR: 0.277, CiteScore: 1)
Advances in Agronomy     Full-text available via subscription   (Followers: 12, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 28, SJR: 0.126, CiteScore: 0)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 10, SJR: 0.992, CiteScore: 1)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 10, SJR: 1.551, CiteScore: 4)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 22, SJR: 2.089, CiteScore: 5)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 14, SJR: 0.572, CiteScore: 2)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.61, CiteScore: 7)
Advances in Botanical Research     Full-text available via subscription   (Followers: 2, SJR: 0.686, CiteScore: 2)
Advances in Cancer Research     Full-text available via subscription   (Followers: 29, SJR: 3.043, CiteScore: 6)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 7, SJR: 1.453, CiteScore: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 1.992, CiteScore: 5)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 3)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 27, SJR: 0.156, CiteScore: 1)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.713, CiteScore: 1)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 10, SJR: 1.316, CiteScore: 2)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, SJR: 1.562, CiteScore: 3)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19, SJR: 1.977, CiteScore: 8)
Advances in Computers     Full-text available via subscription   (Followers: 14, SJR: 0.205, CiteScore: 1)
Advances in Dermatology     Full-text available via subscription   (Followers: 15)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 8)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 23)
Advances in Ecological Research     Full-text available via subscription   (Followers: 42, SJR: 2.524, CiteScore: 4)
Advances in Engineering Software     Hybrid Journal   (Followers: 27, SJR: 1.159, CiteScore: 4)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 43, SJR: 5.39, CiteScore: 8)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 1)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 53, SJR: 0.591, CiteScore: 2)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 1.354, CiteScore: 4)
Advances in Genome Biology     Full-text available via subscription   (Followers: 8, SJR: 12.74, CiteScore: 13)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.193, CiteScore: 0)
Advances in Immunology     Full-text available via subscription   (Followers: 37, SJR: 4.433, CiteScore: 6)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 1.163, CiteScore: 2)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 2, SJR: 1.938, CiteScore: 3)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6, SJR: 0.176, CiteScore: 0)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 3)
Advances in Life Course Research     Hybrid Journal   (Followers: 8, SJR: 0.682, CiteScore: 2)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Marine Biology     Full-text available via subscription   (Followers: 14, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 11, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 6, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 21)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 8)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.182, CiteScore: 0)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 3)
Advances in Oncobiology     Full-text available via subscription   (Followers: 1)
Advances in Organ Biology     Full-text available via subscription   (Followers: 1)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 16, SJR: 1.875, CiteScore: 4)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 6, SJR: 0.174, CiteScore: 0)
Advances in Parasitology     Full-text available via subscription   (Followers: 5, SJR: 1.579, CiteScore: 4)
Advances in Pediatrics     Full-text available via subscription   (Followers: 24, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 10)
Advances in Pharmacology     Full-text available via subscription   (Followers: 16, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.574, CiteScore: 1)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.109, CiteScore: 1)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 8)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 19, SJR: 0.791, CiteScore: 2)
Advances in Psychology     Full-text available via subscription   (Followers: 59)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.371, CiteScore: 1)
Advances in Radiation Oncology     Open Access   (SJR: 0.263, CiteScore: 1)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.101, CiteScore: 0)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 5)
Advances in Space Research     Full-text available via subscription   (Followers: 385, SJR: 0.569, CiteScore: 2)
Advances in Structural Biology     Full-text available via subscription   (Followers: 5)
Advances in Surgery     Full-text available via subscription   (Followers: 10, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 29, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 17)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 46, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 334, SJR: 0.796, CiteScore: 3)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.42, CiteScore: 2)
African J. of Emergency Medicine     Open Access   (Followers: 6, SJR: 0.296, CiteScore: 0)
Ageing Research Reviews     Hybrid Journal   (Followers: 10, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 436, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 43, SJR: 1.272, CiteScore: 3)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 1)
Agriculture and Natural Resources     Open Access   (Followers: 2)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 56, SJR: 1.747, CiteScore: 4)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.589, CiteScore: 3)
Air Medical J.     Hybrid Journal   (Followers: 6, SJR: 0.26, CiteScore: 0)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.19, CiteScore: 0)
Alcohol     Hybrid Journal   (Followers: 11, SJR: 1.153, CiteScore: 3)
Alcoholism and Drug Addiction     Open Access   (Followers: 9)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.604, CiteScore: 3)
Alexandria J. of Medicine     Open Access   (Followers: 1, SJR: 0.191, CiteScore: 1)
Algal Research     Partially Free   (Followers: 10, SJR: 1.142, CiteScore: 4)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.504, CiteScore: 1)
Allergology Intl.     Open Access   (Followers: 5, SJR: 1.148, CiteScore: 2)
Alpha Omegan     Full-text available via subscription   (SJR: 3.521, CiteScore: 6)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 9, SJR: 0.201, CiteScore: 1)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 50, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 4, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 4, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 6)
American Heart J.     Hybrid Journal   (Followers: 50, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 51, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 44, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 10)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 32, SJR: 7.45, CiteScore: 8)
American J. of Infection Control     Hybrid Journal   (Followers: 26, SJR: 1.062, CiteScore: 2)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 34, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 43)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3, SJR: 1.967, CiteScore: 2)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 202, SJR: 2.7, CiteScore: 4)
American J. of Ophthalmology     Hybrid Journal   (Followers: 62, SJR: 3.184, CiteScore: 4)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 6, SJR: 0.265, CiteScore: 0)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.289, CiteScore: 1)
American J. of Otolaryngology     Hybrid Journal   (Followers: 25, SJR: 0.59, CiteScore: 1)
American J. of Pathology     Hybrid Journal   (Followers: 27, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 27, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 37, SJR: 1.141, CiteScore: 2)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.767, CiteScore: 1)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 6)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.144, CiteScore: 3)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 63, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 15, SJR: 0.411, CiteScore: 1)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 3, SJR: 0.277, CiteScore: 0)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription  
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 5, SJR: 4.849, CiteScore: 10)
Analytica Chimica Acta     Hybrid Journal   (Followers: 39, SJR: 1.512, CiteScore: 5)
Analytical Biochemistry     Hybrid Journal   (Followers: 173, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 10, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 11)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 2)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 23, SJR: 0.683, CiteScore: 2)
Angiología     Full-text available via subscription   (SJR: 0.121, CiteScore: 0)
Angiologia e Cirurgia Vascular     Open Access   (Followers: 1, SJR: 0.111, CiteScore: 0)

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Journal Cover
Analytical Biochemistry
Journal Prestige (SJR): 0.633
Citation Impact (citeScore): 2
Number of Followers: 173  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0003-2697 - ISSN (Online) 1096-0309
Published by Elsevier Homepage  [3163 journals]
  • Development of DNAzyme-based PCR signal cascade amplification for visual
           detection of Listeria monocytogenes in food
    • Authors: Zhanmin Liu; Chenhui Yao; Cuiyun Yang; Yanming Wang; Sibao Wan; Junyi Huang
      Abstract: Publication date: 15 July 2018
      Source:Analytical Biochemistry, Volume 553
      Author(s): Zhanmin Liu, Chenhui Yao, Cuiyun Yang, Yanming Wang, Sibao Wan, Junyi Huang
      Listeria monocytogenes is an important foodborne pathogen, and it can cause severe diseases. Rapid detection of L. monocytogenes is crucial to control this pathogen. A simple and robust strategy based on the cascade of PCR and G-quadruplex DNAzyme catalyzed reaction was used to detect L. monocytogenes. In the presence of hemin and the aptamer formed during PCR, the catalytic horseradish peroxidase-mimicking G-quadruplex DNAzymes allow the colorimetric responses of target DNA from L. monocytogenes. This assay can detect genomic DNA of L. monocytogenes specifically with as low as 50 pg/reaction with the naked eye. Through 20 pork samples assay, visual detection assay had the same results as conventional detection methods, and had a good performance. This is a powerful demonstration of the ability of G-quadruplex DNAzyme to be used for PCR-based assay with significant advantages of high sensitivity, low cost and simple manipulation over existing approaches and offers the opportunity for application in pathogen detection.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.015
      Issue No: Vol. 553 (2018)
  • Magnetic nanocomposite of chitosan-Schiff base grafted graphene oxide for
           lead analysis in whole blood
    • Authors: Shahram Seidi; Mahshid Majd; Maryam Rezazadeh; Maryam Shanehsaz
      Abstract: Publication date: 15 July 2018
      Source:Analytical Biochemistry, Volume 553
      Author(s): Shahram Seidi, Mahshid Majd, Maryam Rezazadeh, Maryam Shanehsaz
      A new Schiff base grafted graphene oxide-magnetic chitosan was utilized as a novel sorbent for extraction and quantification of lead ion in blood samples via dispersive magnetic solid phase extraction. The prepared nanocomposite sorbent was characterized by SEM, TEM, FT-IR, XRD, VSM and EDX and the quantification analysis was performed by microsampling flame atomic absorption spectrometry. The important parameters on the extraction efficiency were thoroughly optimized by means of experimental design. Under the optimized conditions, an aliquot of 50 mL of sample (pH 6.3) was extracted utilizing 60 mg of magnetic nanoparticles during 30 min. The sorbent was afterward desorbed using 1.0 mL of 0.8 mol L−1 HNO3 under fierce vortex for 6 min. A preconcentration factor of 20 and an absolute recovery of 40% were provided by the proposed method. The limits of detection (3S/N) and quantification (10 S/N) were 0.06 ng mL−1 and 2.0 ng mL−1, respectively. An excellent linearity was achieved within the range of (10–800) ng mL−1 and the regression coefficient was 0.9903. The intra- and inter-day RSDs% were found to be 1.8% and 7.0%, respectively. Furthermore, the method was applied for analysis of blood samples and good accuracies within the range of 97%–108% were obtained.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.018
      Issue No: Vol. 553 (2018)
  • An assay of optimal cytochrome c oxidase activity in fish gills
    • Authors: Yau-Chung Hu; Meng-Han Chung; Tsung-Han Lee
      Abstract: Publication date: 15 July 2018
      Source:Analytical Biochemistry, Volume 553
      Author(s): Yau-Chung Hu, Meng-Han Chung, Tsung-Han Lee
      Cytochrome c oxidase (COX) catalyzes the terminal oxidation reaction in the electron transport chain (ETC) of aerobic respiratory systems. COX activity is an important indicator for the evaluation of energy production by aerobic respiration in various tissues. On the basis of the respiratory characteristics of muscle, we established an optimal method for the measurement of maximal COX activity. To validate the measurement of cytochrome c absorbance, different ionic buffer concentrations and tissue homogenate protein concentrations were used to investigate COX activity. The results showed that optimal COX activity is achieved when using 50–100 μg fish gill homogenate in conjunction with 75–100 mM potassium phosphate buffer. Furthermore, we compared branchial COX activities among three species of euryhaline teleost (Chanos chanos, Oreochromis mossambicus, and Oryzias dancena) to investigate differences in aerobic respiration of osmoregulatory organs. COX activities in the gills of these three euryhaline species were compared with COX subunit 4 (COX4) protein levels. COX4 protein abundance and COX activity patterns in the three species occurring in environments with various salinities increased when fish encountered salinity challenges. This COX activity assay therefore provides an effective and accurate means of assessing aerobic metabolism in fish.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.017
      Issue No: Vol. 553 (2018)
  • Assay for abscisic acid 8′-hydroxylase activity of cloned plant
           cytochrome P450 oxidases in Saccharomyces cerevisiae
    • Authors: Stella Eggels; Viktoriya Avramova; Chris-Carolin Schön; Brigitte Poppenberger; Wilfried Rozhon
      Abstract: Publication date: 15 July 2018
      Source:Analytical Biochemistry, Volume 553
      Author(s): Stella Eggels, Viktoriya Avramova, Chris-Carolin Schön, Brigitte Poppenberger, Wilfried Rozhon
      The plant hormone abscisic acid (ABA) regulates many processes, including response to drought, seed dormancy and abscission of leaves and fruits. For maintenance of ABA homeostasis, catabolism of ABA by 8′-hydroxylation and subsequent cyclisation to phaseic acid (PA) is crucial. However, detection of ABA 8′-hydroxylation activity is tedious. We present a simple and rapid method for detection of ABA 8′-hydroxylase activity by cloning cDNAs of interest and expressing the respective protein in yeast. Upon addition of ABA, PA is formed and subsequently quantified in the yeast cell culture supernatant by heart cutting 2D-HPLC or GC-MS.
      Graphical abstract image

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.011
      Issue No: Vol. 553 (2018)
  • Metabolomics analysis of the potential anticancer mechanism of annonaceous
           acetogenins on a multidrug resistant mammary adenocarcinoma cell
    • Authors: Chengyao Ma; Yue Li; Hanqing Wu; Junyang Ji; Qianqian Sun; Yilin Song; Shen Wang; Xiang Li; Yong Chen; Jianwei Chen
      Pages: 1 - 6
      Abstract: Publication date: 15 July 2018
      Source:Analytical Biochemistry, Volume 553
      Author(s): Chengyao Ma, Yue Li, Hanqing Wu, Junyang Ji, Qianqian Sun, Yilin Song, Shen Wang, Xiang Li, Yong Chen, Jianwei Chen
      Although annonaceous acetogenins (ACGs) have been reported to have antitumor activity for over three decades, and many of the underlying mechanism of ACGs on cancer have been clarified, there are still outstanding issues. In particular, the changes of small metabolite in cancer cells, caused by ACGs intake, have been reported rarely. Recent research has showed that cellular metabolic profiling coupled with ultra-flow liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UFLC-Q-TOF-MS) and multivariable statistical analysis enables a good understanding of ACGs' effects on multidrug resistant human mammary adenocarcinoma (MCF-7/Adr) cells. As a result, 23 potential biomarkers (p < 0.05, VIP >1) were identified, and 5 pathways (impact-value > 0.10) identified. The differential metabolites suggested that ACGs affected metabolomics pathways, including arginine and proline metabolism, glycerophospholipid metabolism, taurine and hypotaurine metabolism, alanine, aspartate and glutamate metabolism and D-Glutamine and D-glutamate metabolism.
      Graphical abstract image

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.04.022
      Issue No: Vol. 553 (2018)
  • Electrochemical enzymatic fenitrothion sensor based on a
           tyrosinase/poly(2-hydroxybenzamide)-modified graphite electrode
    • Authors: Maria de Fátima Alves; Ricardo Augusto Moreira de Souza Corrêa; Filipe Soares da Cruz; Diego Leoni Franco; Lucas Franco Ferreira
      Pages: 15 - 23
      Abstract: Publication date: 15 July 2018
      Source:Analytical Biochemistry, Volume 553
      Author(s): Maria de Fátima Alves, Ricardo Augusto Moreira de Souza Corrêa, Filipe Soares da Cruz, Diego Leoni Franco, Lucas Franco Ferreira
      This paper reports the electrosynthesis and characterisation of a polymeric film derived from 2-hydroxybenzamide over a graphite electrode and its application as an enzymatic biosensor for the determination and quantification of the pesticide fenitrothion. The material was analysed by scanning electron microscopy and its electrochemical properties characterised by cyclic voltammetry and electrochemical impedance spectroscopy. The enzyme tyrosinase was immobilised over the modified electrode by the drop and dry technique. Catechol was determined by direct reduction of biocatalytically formed o-quinone by employing the flow injection analysis technique. The analytical characteristics of the proposed sensor were optimised as follows: phosphate buffer 0.050 M at pH 6.5, flow rate 5.0 mL min−1, sample injection volume 150 μL, catechol concentration 1.0 mM and maximum inhibition time by fenitrothion of 6 min. The biosensors showed a linear response to pesticide concentration from 0.018 to 3.60 μM. The limit of detection and limit of quantification were calculated as 4.70 nM and 15.9 nM (RSD < 2.7%), respectively. The intra- and inter-electrode RSDs were 3.35% (n = 15) and 8.70% (n = 7), respectively. In addition, water samples spiked with the pesticide showed an average recovery of 97.6% (±1.53).
      Graphical abstract image

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.014
      Issue No: Vol. 553 (2018)
  • Feature-preserving noise reduction by using time-domain Gaussian-weighted
           multiple noise reduction filters for real-time bioluminescence measurement
    • Authors: Keisuke Ishigami; Hiromitsu Furukawa
      Pages: 1 - 3
      Abstract: Publication date: 15 June 2018
      Source:Analytical Biochemistry, Volume 551
      Author(s): Keisuke Ishigami, Hiromitsu Furukawa
      This paper proposes a time-domain Gaussian-weighted noise reduction filter for bioluminescence measurement with low signal-to-noise ratio through photon counting. The filter was used for estimating the true fold-change signal from noisy gene expression data obtained through real-time dual-color luciferase assay. Furthermore, not only was the higher harmonics noise of the measurement system confirmed to reduce from the gene expression data but rapid and slow changes were also preserved in the estimated signal. In addition, the probability value of Pearson's chi-squared test was improved 257 times at most and 1.5 times on average without impairing the noise reduction ratio.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.04.026
      Issue No: Vol. 551 (2018)
  • Clinical evaluation of a novel and simple-to-use molecular platform for
           diagnosis of respiratory syncytial virus
    • Authors: Karoliina Liikonen; Tuomas Ojalehto; Sonja Elf; Minna Mäki; Pirjo Matero; Kevin E. Eboigbodin
      Pages: 4 - 6
      Abstract: Publication date: 15 June 2018
      Source:Analytical Biochemistry, Volume 551
      Author(s): Karoliina Liikonen, Tuomas Ojalehto, Sonja Elf, Minna Mäki, Pirjo Matero, Kevin E. Eboigbodin
      Rapid molecular diagnostic testing for respiratory infections can improve patient care and minimize unnecessary prescriptions of antibiotics. We present the preliminary clinical evaluation of Orion GenRead® RSV, a novel, rapid, and easy-to-use molecular test for the diagnosis of respiratory syncytial virus (RSV) infection. The sensitivity and specificity of Orion GenRead RSV were 99% and 100%, respectively. Orion GenRead RSV detected RSV-positive specimens within 15 min. The performance of Orion GenRead RSV was similar to that of the reference method and this test could rapidly detect RSV within minutes. Orion GenRead RSV is applicable for near-patient testing.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.04.017
      Issue No: Vol. 551 (2018)
  • Ultrasonic assisted magnetic dispersive solid phase microextraction for
           pre concentration of serotonin–norepinephrine reuptake inhibitor drugs
    • Authors: Mahdi Ghorbani; Mahmoud Chamsaz; Mohsen Aghamohammadhasan; Alireza Shams
      Pages: 7 - 18
      Abstract: Publication date: 15 June 2018
      Source:Analytical Biochemistry, Volume 551
      Author(s): Mahdi Ghorbani, Mahmoud Chamsaz, Mohsen Aghamohammadhasan, Alireza Shams
      A simple and sensitive ultrasonic assisted magnetic dispersive solid phase microextraction method (UAMDSPME) coupled with high performance liquid chromatography was developed to determine serotonin–norepinephrine reuptake inhibitor drugs including duloxetine (DUL), venlafaxine (VEN) and atomoxetine (ATO) in human urine, river water and well water samples. A novel and efficient SPME sorbent, magnetic p-Phenylenediamine functionalized reduced graphene oxide Quantum Dots@ Ni nanocomposites (MrGOQDs–PD@ Ni), was prepared and applied for extraction of the analytes. Several effective parameters on the extraction efficiency of the analytes were investigated and optimized with experimental design approach. The performance of MrGOQDs–PD@ Ni as the SPME sorbent for the extraction of DUL, VEN and ATO was then compared with magnetic graphene oxide (MGO@Fe3O4) and magnetic reduced graphene oxide (MrGO@ Ni). Under the optimized conditions for the MrGOQDs–PD@ Ni sorbent, the intra-day relative standard deviations (RSDs, n = 5) and the limits of detections (LODs) were lower than 4.6% and 1.1 ngmL−1, respectively. Moreover, the good linear ranges were observed in wide concentration ranges with R-squared larger than 0.9878. Finally, the enrichment factors in the range of 137–183 and the recovery percentage in the range of 89.2–94.8% were obtained to determine the analytes in the real samples.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.003
      Issue No: Vol. 551 (2018)
  • Continuous thrombin generation in whole blood: New applications for
           assessing activators and inhibitors of coagulation
    • Authors: Shannon M. Prior; Kenneth G. Mann; Kalev Freeman; Saulius Butenas
      Pages: 19 - 25
      Abstract: Publication date: 15 June 2018
      Source:Analytical Biochemistry, Volume 551
      Author(s): Shannon M. Prior, Kenneth G. Mann, Kalev Freeman, Saulius Butenas
      Hemostatic tests have been utilized to clarify the blood coagulation potential. The novel thrombin generation (TG) assay of this study provides explicit information and is the most physiologically-relevant hemostatic test ex vivo. We describe how this assay allows for TG under a number of relevant circumstances. First, whole blood (WB) from healthy individuals was analyzed ± 5 pM tissue factor (TF) and ± contact pathway inhibition. Without an exogenous initiator TG was decreased and delayed, but addition of 5 pM TF shortened the lag phase and increased peak thrombin. Additional experiments included fresh WB from a trauma patient analyzed for endogenous activity and TG from healthy donors subjected to TG antagonists which prolonged the lag phase whereas TG agonists consistently shortened the lag phase in a dose dependent manner. Lastly, platelet-poor plasma was reconstituted with packed red blood cells and TG was monitored in the presence and absence of both TF as an activator and PCPS as a phospholipid surface. Our data illustrate the potential that this continuous TG assay has in the evaluation of disorders relevant to blood coagulation and in the monitoring of treatments administered in response to these disorders.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.005
      Issue No: Vol. 551 (2018)
  • Adaptation of an amplicon-based human cancer next-generation sequencing
           panel assay for murine tumors
    • Authors: David R. Meier; Kristopher A. Lofgren; Grzegorz T. Gurda; Paraic A. Kenny
      Pages: 26 - 28
      Abstract: Publication date: 15 June 2018
      Source:Analytical Biochemistry, Volume 551
      Author(s): David R. Meier, Kristopher A. Lofgren, Grzegorz T. Gurda, Paraic A. Kenny
      Unlike humans, inbred genetically engineered mice have minimal inter-individual variation and, consequently, offer substantially increased statistical power for robust definition of recurrent cooperating cancer mutations. While technically feasible, whole exome sequencing is expensive and extremely data-intensive. Somatic mutation analysis using panels of 25–75 genes now provides detailed insight into the biology of human tumors. Here we report an adaptation for mouse tumors of a human PCR amplicon-based panel (Ion Torrent Cancer Hotspot Panel v2) allowing analysis of 18 cancer genes, including Kras, Nras, Hras, Pten, Pik3ca and Smad4, and encompassing regions homologous to more than 2000 known human cancer mutations.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.007
      Issue No: Vol. 551 (2018)
  • Enhanced amperometric detection of paracetamol by immobilized cobalt ion
           on functionalized MWCNTs - Chitosan thin film
    • Authors: Shamima Akhter; Wan Jefrey Basirun; Yatimah Alias; Mohd Rafie Johan; Samira Bagheri; Md. Shalauddin; Magaji Ladan; Nadzirah Sofia Anuar
      Pages: 29 - 36
      Abstract: Publication date: 15 June 2018
      Source:Analytical Biochemistry, Volume 551
      Author(s): Shamima Akhter, Wan Jefrey Basirun, Yatimah Alias, Mohd Rafie Johan, Samira Bagheri, Md. Shalauddin, Magaji Ladan, Nadzirah Sofia Anuar
      In the present study, a nanocomposite of f-MWCNTs-chitosan-Co was prepared by the immobilization of Co(II) on f-MWCNTs-chitosan by a self-assembly method and used for the quantitative determination of paracetamol (PR). The composite was characterized by field emission scanning electron microscopy (FESEM) and energy dispersive x-ray analysis (EDX). The electroactivity of cobalt immobilized on f-MWCNTs-chitosan was assessed during the electro-oxidation of paracetamol. The prepared GCE modified f-MWCNTs/CTS-Co showed strong electrocatalytic activity towards the oxidation of PR. The electrochemical performances were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Under favorable experimental conditions, differential pulse voltammetry showed a linear dynamic range between 0.1 and 400 μmol L−1 with a detection limit of 0.01 μmol L−1 for the PR solution. The fabricated sensor exhibited significant selectivity towards PR detection. The fabricated sensor was successfully applied for the determination of PR in commercial tablets and human serum sample.
      Graphical abstract image

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.004
      Issue No: Vol. 551 (2018)
  • Selection and characterization, application of a DNA aptamer targeted to
           Streptococcus pyogenes in cooked chicken
    • Authors: Yukun Huang; Xin Wang; Nuo Duan; Yu Xia; Zhouping Wang; Zhenming Che; Lijun Wang; Xiao Yang; Xianggui Chen
      Pages: 37 - 42
      Abstract: Publication date: 15 June 2018
      Source:Analytical Biochemistry, Volume 551
      Author(s): Yukun Huang, Xin Wang, Nuo Duan, Yu Xia, Zhouping Wang, Zhenming Che, Lijun Wang, Xiao Yang, Xianggui Chen
      An aptamer against Streptococcus pyogenes was selected and identified, and a fluorescent method based on the reported aptamer was established to detect S. pyogenes in the cooked chicken. Through a twelve rounds of whole-bacterium SELEX (systematic evolution of ligands by exponential enrichment) selection in vitro, a set of aptamers binding to the whole cell of S. pyogenes were generated, harvesting a low-level dissociation constant (K d ) value of 44 ± 5 nmol L−1 of aptamer S-12. Aptamer-based quantification of S. pyogenes in the cooked chicken sample was implemented in a fluorescence resonance energy transfer-based assay by using graphene oxide, resulting in a limit of detection of 70 cfu mL−1. The selected aptamer showed affinity and selectivity recognizing S. pyogenes; besides, more biosensors based on the selected aptamer as a molecular recognition element could be developed in the innovative determinations of S. pyogenes.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.04.015
      Issue No: Vol. 551 (2018)
  • Analysis of respiratory capacity in brain tissue preparations:
           high-resolution respirometry for intact hippocampal slices
    • Authors: Cândida Dias; Cátia F. Lourenço; Rui M. Barbosa; João Laranjinha; Ana Ledo
      Pages: 43 - 50
      Abstract: Publication date: 15 June 2018
      Source:Analytical Biochemistry, Volume 551
      Author(s): Cândida Dias, Cátia F. Lourenço, Rui M. Barbosa, João Laranjinha, Ana Ledo
      The evaluation of mitochondrial function provides the basis for the study of brain bioenergetics. However, analysis of brain mitochondrial respiration has been hindered by the low yield associated with mitochondria isolation procedures. Furthermore, isolating mitochondria or cells results in loss of the inherent complexity of the central nervous system. High-resolution respirometry (HRR), is a valuable tool to study mitochondrial function and has been used in diverse biological preparations ranging from isolated mitochondria to tissue homogenates and permeabilized tissue biopsies. Here we describe a novel methodology for evaluation of mitochondrial respiration using tissue preparations from the central nervous system, namely acute hippocampal slices from rodents, with HRR. By using acute intact hippocampal slices, tissue cytoarchitecture, intercellular communication and connectivity are preserved. Mitochondrial respiration was evaluated by using an adapted substrate-uncoupler-inhibitor titration (SUIT) protocol and the expected responses were observed. This methodology can be used to detect differences in mitochondrial function at the oxidative phosphorylation level and for studies with different brain oxidative substrates in physiological and neuropathological settings, by using a system that better represents the in vivo conditions than isolated mitochondria and/or cells.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.ab.2018.05.010
      Issue No: Vol. 551 (2018)
  • Prediction of lysine glutarylation sites by maximum relevance minimum
           redundancy feature selection
    • Authors: Zhe Ju; Jian-Jun He
      Pages: 1 - 7
      Abstract: Publication date: 1 June 2018
      Source:Analytical Biochemistry, Volume 550
      Author(s): Zhe Ju, Jian-Jun He
      Lysine glutarylation is new type of protein acylation modification in both prokaryotes and eukaryotes. To better understand the molecular mechanism of glutarylation, it is important to identify glutarylated substrates and their corresponding glutarylation sites accurately. In this study, a novel bioinformatics tool named GlutPred is developed to predict glutarylation sites by using multiple feature extraction and maximum relevance minimum redundancy feature selection. On the one hand, amino acid factors, binary encoding, and the composition of k-spaced amino acid pairs features are incorporated to encode glutarylation sites. And the maximum relevance minimum redundancy method and the incremental feature selection algorithm are adopted to remove the redundant features. On the other hand, a biased support vector machine algorithm is used to handle the imbalanced problem in glutarylation sites training dataset. As illustrated by 10-fold cross-validation, the performance of GlutPred achieves a satisfactory performance with a Sensitivity of 64.80%, a Specificity of 76.60%, an Accuracy of 74.90% and a Matthew's correlation coefficient of 0.3194. Feature analysis shows that some k-spaced amino acid pair features play the most important roles in the prediction of glutarylation sites. The conclusions derived from this study might provide some clues for understanding the molecular mechanisms of glutarylation.

      PubDate: 2018-04-15T10:34:19Z
      DOI: 10.1016/j.ab.2018.04.005
      Issue No: Vol. 550 (2018)
  • Principal coordinate analysis assisted chromatographic analysis of
           bacterial cell wall collection: A robust classification approach
    • Authors: Keshav Kumar; Felipe Cava
      Pages: 8 - 14
      Abstract: Publication date: 1 June 2018
      Source:Analytical Biochemistry, Volume 550
      Author(s): Keshav Kumar, Felipe Cava
      In the present work, Principal coordinate analysis (PCoA) is introduced to develop a robust model to classify the chromatographic data sets of peptidoglycan sample. PcoA captures the heterogeneity present in the data sets by using the dissimilarity matrix as input. Thus, in principle, it can even capture the subtle differences in the bacterial peptidoglycan composition and can provide a more robust and fast approach for classifying the bacterial collection and identifying the novel cell wall targets for further biological and clinical studies. The utility of the proposed approach is successfully demonstrated by analysing the two different kind of bacterial collections. The first set comprised of peptidoglycan sample belonging to different subclasses of Alphaproteobacteria. Whereas, the second set that is relatively more intricate for the chemometric analysis consist of different wild type Vibrio Cholerae and its mutants having subtle differences in their peptidoglycan composition. The present work clearly proposes a useful approach that can classify the chromatographic data sets of chromatographic peptidoglycan samples having subtle differences. Furthermore, present work clearly suggest that PCoA can be a method of choice in any data analysis workflow.

      PubDate: 2018-04-15T10:34:19Z
      DOI: 10.1016/j.ab.2018.04.008
      Issue No: Vol. 550 (2018)
  • Determination of enantiomeric excess of some amino acids by second-order
           calibration of kinetic-fluorescence data
    • Authors: Azadeh Naghashian-Haghighi; Bahram Hemmateenejad; Mojtaba Shamsipur
      Pages: 15 - 26
      Abstract: Publication date: 1 June 2018
      Source:Analytical Biochemistry, Volume 550
      Author(s): Azadeh Naghashian-Haghighi, Bahram Hemmateenejad, Mojtaba Shamsipur
      In this investigation a new non-separative kinetic-spectroflourimetric method is proposed for the determination of lysine (lys), leucine (leu) and phenylalanine (phe) enantiomers as their o-phthaldialdehyde (OPA) derivatives in the presence of an optically active chiral thiol compound, 1-mercapto-2-propanol (MP). At ambient temperature and in the borate buffer media of pH 9.6, MP, OPA, as highly selective fluorogenic reagents, and amino acid (AA) enantiomers reacts with each other to yield two fluorescent diasteriomers of D and L-AA with maximum difference in fluorescence intensity at about 450 nm. To achieve information from the small spectral changes, the data are analyzed by Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) method. Linear calibration curves are achieved to distinct D and L-lys, leu and phe in different mole ratios by applying appropriate constraints in MCR-ALS procedures. This is the first application of MCR-ALS in determination of enantiomeric excess (ee) using OPA/MP adduct as chiral reagent, which benefits from direct time dependent-fluorescence spectral analysis and does not require prior separation of chiral analytes. Both the cross-validated correlation coefficient (Q 2) and root mean squares error of prediction (RMSEP) indicated satisfactory prediction ability of this method.

      PubDate: 2018-04-15T10:34:19Z
      DOI: 10.1016/j.ab.2018.04.004
      Issue No: Vol. 550 (2018)
  • Development of Quenching-qPCR (Q-Q) assay for measuring absolute
           intracellular cleavage efficiency of ribozyme
    • Authors: Min Woo Kim; Gwanggyu Sun; Jung Hyuk Lee; Byung-gee Kim
      Pages: 27 - 33
      Abstract: Publication date: 1 June 2018
      Source:Analytical Biochemistry, Volume 550
      Author(s): Min Woo Kim, Gwanggyu Sun, Jung Hyuk Lee, Byung-gee Kim
      Ribozyme (Rz) is a very attractive RNA molecule in metabolic engineering and synthetic biology fields where RNA processing is required as a control unit or ON/OFF signal for its cleavage reaction. In order to use Rz for such RNA processing, Rz must have highly active and specific catalytic activity. However, current methods for assessing the intracellular activity of Rz have limitations such as difficulty in handling and inaccuracies in the evaluation of correct cleavage activity. In this paper, we proposed a simple method to accurately measure the “intracellular cleavage efficiency” of Rz. This method deactivates unwanted activity of Rz which may consistently occur after cell lysis using DNA quenching method, and calculates the cleavage efficiency by analyzing the cleaved fraction of mRNA by Rz from the total amount of mRNA containing Rz via quantitative real-time PCR (qPCR). The proposed method was applied to measure “intracellular cleavage efficiency” of sTRSV, a representative Rz, and its mutant, and their intracellular cleavage efficiencies were calculated as 89% and 93%, respectively.

      PubDate: 2018-04-15T10:34:19Z
      DOI: 10.1016/j.ab.2018.04.007
      Issue No: Vol. 550 (2018)
  • Rapid quantification of vesicle concentration for DOPG/DOPC and
           Cardiolipin/DOPC mixed lipid systems of variable composition
    • Authors: Margaret M. Elmer-Dixon; Bruce E. Bowler
      First page: 448a
      Abstract: Publication date: 15 July 2018
      Source:Analytical Biochemistry, Volume 553
      Author(s): Margaret M. Elmer-Dixon, Bruce E. Bowler
      A novel approach to quantify mixed lipid systems is described. Traditional approaches to lipid vesicle quantification are time consuming, require large amounts of material and are destructive. We extend our recently described method for quantification of pure lipid systems to mixed lipid systems. The method only requires a UV–Vis spectrometer and does not destroy sample. Mie scattering data from absorbance measurements are used as input into a Matlab program to calculate the total vesicle concentration and the concentrations of each lipid in the mixed lipid system. The technique is fast and accurate, which is essential for analytical lipid binding experiments.

      PubDate: 2018-05-28T13:20:12Z
      DOI: 10.1016/j.bpj.2017.11.2476
      Issue No: Vol. 114, No. 3 (2018)
  • An efficient method to evaluate experimental factor influence on in vitro
           binding of aptamers
    • Abstract: Publication date: Available online 18 June 2018
      Source:Analytical Biochemistry
      Author(s): Donglin Diao, Na Qiao, Xiao Wu, Jiyuan Li, Xinhui Lou
      Nucleic acid-based aptamers are promising alternative to antibodies, however, their selection process (SELEX) is challenging. A number of simulations and few experiments have been reported offering insights into experimental factors (EFs) that govern the effectiveness of the selection process. Though useful, these previous studied were either lack of experimental confirmation, or considered limited EFs. A more efficient experimental method is highly desired. In this study, we developed a fast method that is capable to quantitatively probe the influence of multiple EFs. Based on the fact that the aptamer enrichment efficiency is highly affected by background binding, the binding ratio between the numbers of specific aptamer binders and nonspecific (unselected library) binders per bead was used to quantitatively evaluate EF effects. Taking thrombin and streptavidin as models, three previously studied EFs (surface coverage, buffer composition, and DNA concentration) and four never-studied ones (surface chemistry, heat treatment, elution methodology and pool purity) were investigated. The EFs greatly affected binding ratio (ranging from 0.03 ± 0.03 to 14.60 ± 2.30). The results were in good agreement with the literature, suggesting the good feasibility of our method. Our study provides guidance for the choice of EFs not only for aptamer selection, but also for binding evaluation of aptamers.

      PubDate: 2018-06-20T06:44:56Z
  • Isothermal amplification using modified primers for rapid electrochemical
           analysis of coeliac disease associated DQB1*02 HLA allele
    • Abstract: Publication date: Available online 18 June 2018
      Source:Analytical Biochemistry
      Author(s): Sallam Al-Madhagi, Hamdi Joda, Miriam Jauset-Rubio, Mayreli Ortiz, Ioanis Katakis, Ciara K. O'Sullivan
      DNA biosensors are attractive tools for genetic analysis as there is an increasing need for rapid and low-cost DNA analysis, primarily driven by applications in personalized pharmacogenomics, clinical diagnostics, rapid pathogen detection, food traceability and forensics. A rapid electrochemical genosensor detection methodology exploiting a combination of modified primers for solution-phase isothermal amplification, followed by rapid detection via hybridization on gold electrodes is reported. Modified reverse primers, exploiting a C18 spacer between the primer-binding site and an engineered single stranded tail, are used in a recombinase polymerase amplification reaction to produce an amplicon with a central duplex flanked by two single stranded tails. These tails are designed to be complementary to a gold electrode tethered capture oligo probe as well as a horseradish peroxidase labelled reporter oligo probe. The time required for hybridization of the isothermally generated amplicons with each of the immobilized and reporter probes was optimised to be 2 min, in both cases. The effect of amplification time and the limit of detection were evaluated using these hybridization times for both single stranded and double stranded DNA templates. The best detection limit of 70 fM for a ssDNA template was achieved using 45 min amplification, whilst for a dsDNA template, just 30 min amplification resulted in a slightly lower detection limit of 14 fM, whilst both 20 and 45 min amplification times were observed to provide detection limits of 71 and 72 fM, respectively, but 30 and 45 min amplification resulted in a much higher signal and sensitivity. The genosensor was applied to genomic DNA and real patient and control blood samples for detection of the DQB1*02 HLA allele, as a model system, demonstrating the possibility to carry out molecular diagnostics, combining amplification and detection in a rapid and facile manner.

      PubDate: 2018-06-20T06:44:56Z
  • Imaging DNA single-strand breaks generated by reactive oxygen species
           using a liquid crystal-based sensor
    • Abstract: Publication date: Available online 18 June 2018
      Source:Analytical Biochemistry
      Author(s): Hyeong Jin Kim, Chang-Hyun Jang
      DNA single-strand breaks (SSBs) have attracted much interest since they are highly related to carcinogenesis and ageing. Herein, we report a new liquid crystal (LC)-based sensor for the detection of DNA SSBs generated by reactive oxygen species (ROS) created from the Fenton reaction. The adsorption of single-stranded DNA (ssDNA) onto the cationic surfactant-laden aqueous/LC interface interferes with the surfactant layer, inducing a planar orientation of the LCs. However, the DNA SSBs generated by the Fenton reaction-produced ROS result in a decrease of the electrostatic interactions between the ssDNA and cationic surfactant molecules, causing rearrangement of the surfactant layer and reorientation of the LCs back to a homeotropic alignment. The changes in orientation of the LCs caused by the DNA SSBs are simply converted and observed as a shift from a bright optical image of the LCs to a dark one under a polarized light microscope. With this simple LC-based approach, the DNA SSBs could be detected more effectively and rapidly without any complex instrumentation or intricate processes. Therefore, our research provides a novel strategy for the detection of DNA damage as well as better insight into the DNA-damaging process.
      Graphical abstract image

      PubDate: 2018-06-20T06:44:56Z
  • Classifying the molecular functions of Rab GTPases in membrane trafficking
           using deep convolutional neural networks
    • Abstract: Publication date: 15 August 2018
      Source:Analytical Biochemistry, Volume 555
      Author(s): Nguyen-Quoc-Khanh Le, Quang-Thai Ho, Yu-Yen Ou
      Deep learning has been increasingly used to solve a number of problems with state-of-the-art performance in a wide variety of fields. In biology, deep learning can be applied to reduce feature extraction time and achieve high levels of performance. In our present work, we apply deep learning via two-dimensional convolutional neural networks and position-specific scoring matrices to classify Rab protein molecules, which are main regulators in membrane trafficking for transferring proteins and other macromolecules throughout the cell. The functional loss of specific Rab molecular functions has been implicated in a variety of human diseases, e.g., choroideremia, intellectual disabilities, cancer. Therefore, creating a precise model for classifying Rabs is crucial in helping biologists understand the molecular functions of Rabs and design drug targets according to such specific human disease information. We constructed a robust deep neural network for classifying Rabs that achieved an accuracy of 99%, 99.5%, 96.3%, and 97.6% for each of four specific molecular functions. Our approach demonstrates superior performance to traditional artificial neural networks. Therefore, from our proposed study, we provide both an effective tool for classifying Rab proteins and a basis for further research that can improve the performance of biological modeling using deep neural networks.

      PubDate: 2018-06-18T10:30:57Z
  • A molecularly-imprinted-electrochemical-sensor modified with
           nano-carbon-dots with high sensitivity and selectivity for rapid
           determination of glucose
    • Abstract: Publication date: 15 August 2018
      Source:Analytical Biochemistry, Volume 555
      Author(s): Wei Zheng, Haiyan Wu, Yan Jiang, Jicheng Xu, Xin Li, Wenchi Zhang, Fengxian Qiu
      In this work, a novel molecularly imprinted electrochemical sensor (MIECS) based on a glassy carbon electrode (GCE) modified with carbon dots (CDs) and chitosan (CS) for the determination of glucose was proposed for the first time. The use of the environmental-friendly CDs and CS as electrode modifications improved the active area and electron-transport ability substantially, while 3-aminobenzeneboronic acid was used as a functional monomer and glucose as template for the fabrication of molecularly imprinted polymer (MIP) film to detect glucose via differential pulse voltammetry. Transmission electron microscope, Fourier transform infrared spectroscopy, energy dispersive x-ray spectrometry, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were applied to characterize the fabricated sensor. Experimental conditions such as molar ratio of functional monomer to template, volume ratio of CDs to CS, incubation time and elution time were optimized. By using glucose as a model analyte, the MIECS had two assay ranges of 0.5–40 μM and 50–600 μM, and fairly low limit of detection (LOD) of 0.09 μM (S/N = 3) under the optimized conditions. The MIECS also exhibited excellent selectivity, good reproducibility, and stability. The proposed sensor was successfully applied to a preliminary test for glucose analysis in real human blood serum samples.
      Graphical abstract image

      PubDate: 2018-06-18T10:30:57Z
  • Label-free detection of exonuclease III activity and its inhibition based
           on DNA hairpin probe
    • Abstract: Publication date: 15 August 2018
      Source:Analytical Biochemistry, Volume 555
      Author(s): Xiafei Jiang, Haisheng Liu, Farjana Yeasmin Khusbu, Changbei Ma, Anqi Ping, Qiling Zhang, Kefeng Wu, Mingjian Chen
      In this paper, we have developed a label-free and rapid fluorescence assay for the detection of exonuclease III (exo III) activity via thioflavin T (ThT) as the G-quadruplex inducer. In this assay, a hairpin probe (HP) with a 5′-guanine-rich (G-rich) sequence is employed as the substrate for exo III. In the presence of exo III, HP can be digested at 3′-OH termini releasing 5′-G-rich sequence. Then, the 5′-G-rich sequence folds into a G-quadruplex, which can be recognized quickly by the ThT dye resulting in an increase in fluorescence emission. This strategy can detect exo III activity as low as 0.5 U/mL. This assay is simple and of low cost without the requirement of labeling with a fluorophore-quencher pair.

      PubDate: 2018-06-18T10:30:57Z
  • An impedimetric immunosensor for highly sensitive detection of IL-8 in
           human serum and saliva samples: A new surface modification method by
           6-phosphonohexanoic acid for biosensing applications
    • Abstract: Publication date: 1 August 2018
      Source:Analytical Biochemistry, Volume 554
      Author(s): Elif Burcu Aydın, Mustafa Kemal Sezgintürk
      In this study, we fabricated a sensitive and label-free impedimetric immunosensor based on 6-phosphonohexanoic acid (PHA) modified ITO electrode for detection of interleukin-8 (IL-8) in human serum and saliva. PHA was first employed to cancer biomarker sensing platform. Anti-IL-8 antibody was used as a biorecognition element and the detection principle of this immunosensor was based on monitoring specific interaction between anti-IL-8 antibody and IL-8 antigen. The morphological characterization of each electrode modification step was analyzed by scanning electron microscopy (SEM), SEM-energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) while electrochemical characterization was performed by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and single frequency impedance (SFI) techniques. Moreover, the antibody immobilization on the electrode surface was proved Fourier-transform infrared spectroscopy (FTIR) and Raman Spectroscopy. This proposed impedimetric immunosensor exhibited good performances with a wide linear in the range from 0.02 pg/mL to 3 pg/mL as well as a relative low detection limit of 6 fg/mL. The impedimetric immunosensor had a good specificity, stability and reproducibility. This study proved that PHA was a suitable interface material to fabricate an electrochemical biosensor.

      PubDate: 2018-06-18T10:30:57Z
  • Target-triggering multiple-cycle signal amplification strategy for
           ultrasensitive detection of DNA based on QCM and SPR
    • Abstract: Publication date: 15 July 2018
      Source:Analytical Biochemistry, Volume 553
      Author(s): Weiling Song, Xiaoyan Guo, Wenbo Sun, Wenshuo Yin, Peng He, Xiaoyan Yang, Xiaoru Zhang
      Detection of ultralow concentrations of nucleic acid sequences is a central challenge in the early diagnosis of genetic diseases. Herein, we developed a target-triggering cascade multiple cycle amplification for ultrasensitive DNA detection using quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). It was based on the exonuclease Ⅲ (Exo Ⅲ)-assisted signal amplification and the hybridization chain reaction (HCR). The streptavidin-coated Au-NPs (Au-NPs-SA) were assembled on the HCR products as recognition element. Upon sensing of target DNA, the duplex DNA probe triggered the Exo Ⅲ cleavage process, accompanied by generating a new secondary target DNA and releasing target DNA. The released target DNA and the secondary target DNA were recycled. Simultaneously, numerous single strands were liberated and acted as the trigger of HCR to generate further signal amplification, resulting in the immobilization of abundant Au-NPs-SA on the gold substrate. The QCM sensor results were found to be comparable to that achieved using a SPR sensor platform. This method exhibited a high sensitivity toward target DNA with a detection limit of 0.70 fM. The high sensitivity and specificity make this method a great potential for detecting DNA with trace amounts in bioanalysis and clinical biomedicine.

      PubDate: 2018-06-18T10:30:57Z
  • Direct and quantitative electrophoretic detection of covalently closed DNA
           circles formed by in vitro ligation
    • Abstract: Publication date: 15 July 2018
      Source:Analytical Biochemistry, Volume 553
      Author(s): Akiko Mizutani, Masafumi Tanaka
      The typical products of enzymatic circularization of DNA, using DNA ligase or recombinase, are covalently closed and mostly relaxed DNA circles. Because they are difficult to analyze on conventional gels, they are often converted to nicked circles prior to electrophoresis. Herein, we present a sensitive and quantitative procedure for directly analyzing ligated closed circle DNA on agarose gels without additional treatments. Specifically, inclusion of GelStar dye in the gel allowed detection of ligated closed circle DNAs, which were likely super-twisted by being intercalated by GelStar, as discrete bands with good separation from linear DNA of the same sizes.
      Graphical abstract image

      PubDate: 2018-06-18T10:30:57Z
  • Simple colorimetric method to determine the in vitro antioxidant activity
           of different monoterpenes
    • Abstract: Publication date: Available online 15 June 2018
      Source:Analytical Biochemistry
      Author(s): Nehuen Noacco, Boris Rodenak-Kladniew, Margarita García de Bravo, Guillermo R. Castro, German A. Islan
      The development of simple, fast and reproducible techniques that provide information about the antioxidant activity (AA) of different compounds is essential to screen and discover new molecules with potential applications in the therapeutic, cosmetic, toxicological and food fields. Here, a novel and simple colorimetric method (“BCB assay”) is proposed for measuring the AA of chemical compounds by protection of the reporter dye Brilliant Cresyl Blue (BCB) from loss of color due to oxidation by hypochlorite (a physiological oxidant). The decay in BCB blue color (λ max = 634 nm) in the presence of hypochlorite occurred in only 5 min and was used to track the AA of different molecules. Particularly, the AA of monoterpenes was demonstrated and used to quantify them at milimolar concentrations. Natural antioxidants like vitamins C and E, resveratrol, dithiothreitol, N-actyl-l-cysteine and glutathione were used as controls to validate the assay. Linalool, geraniol and 1,8-cineole were tested and showed in vitro AA in a concentration-dependent manner. The monoterpene concentrations providing 50% protection against oxidation (AA50) were 2.3, 36.2 and 135.0 mM for linalool, geraniol and 1,8-cineole respectively, suggesting interesting AA. The method provides a useful, fast, simple and low-cost tool to determine the in vitro AA of different molecules.
      Graphical abstract image

      PubDate: 2018-06-18T10:30:57Z
  • Surveying GPCR solubilisation conditions using surface plasmon resonance
    • Abstract: Publication date: Available online 15 June 2018
      Source:Analytical Biochemistry
      Author(s): Iva Hopkins Navratilova, Tonia Aristotelous, Louise E. Bird, Andrew L. Hopkins
      Biophysical screening techniques, such as surface plasmon resonance, enable detailed kinetic analysis of ligands binding to solubilised G-protein coupled receptors. The activity of a receptor solubilised out of the membrane is crucially dependent on the environment in which it is suspended. Finding the right conditions is challenging due to the number of variables to investigate in order to determine the optimum solubilisation buffer for any given receptor. In this study we used surface plasmon resonance technology to screen a variety of solubilisation conditions including buffers and detergents for two model receptors: CXCR4 and CCR5. We tested 950 different combinations of solubilisation conditions for both receptors. The activity of both receptors was monitored by using conformation dependent monoclonal antibodies and the binding of small molecules ligands. Despite both receptors belonging to the chemokine receptor family they show some differences in their preference for solubilisation conditions that provide the highest level of binding for both the conformation dependent antibodies and small molecules. The study described here is focused not only on finding the best solubilisation conditions for each receptor, but also on factors that determine the sensitivity of the assay for each receptor. We also suggest how these data about different buffers and detergents can be used as a guide for selecting solubilisation conditions for other membrane proteins.

      PubDate: 2018-06-18T10:30:57Z
  • A novel electrochemical DNA biosensor for Ebola virus detection
    • Abstract: Publication date: Available online 14 June 2018
      Source:Analytical Biochemistry
      Author(s): Hoda Ilkhani, Siamak Farhad
      The aim of this study was to fabricate a novel electrochemical-based DNA-sensing device for Ebola virus DNA diagnostic by an enzyme-amplified detection, which improves the sensitivity and selectivity of the sensor. A thiolated DNA capture probe sequence was immobilized on the screen printed electrode surface and hybridized with biotinylated target strand DNA for the fabrication of Ebola DNA-sensing devices. Prior to the electrochemical detection of the enzymatic product by differential pulse voltammetry (DPV) method, the biotinylated hybrid was labelled with a streptavidin-alkaline phosphate conjugate on the surface of the working electrode. All the experiment steps were optimized using electrochemical impedance Spectroscopy (EIS) and the optimum condition for biosensor fabrication was achieved. The last step, the selectivity, reproducibility and sensitivity of fabricated electrochemical DNA biosensor was obtained.

      PubDate: 2018-06-18T10:30:57Z
  • Amplified FRET based CA15-3 immunosensor using antibody functionalized
           luminescent carbon-dots and AuNPs-dendrimer aptamer as donor-acceptor
    • Abstract: Publication date: Available online 14 June 2018
      Source:Analytical Biochemistry
      Author(s): Somayeh Mohammadi, Abdollah Salimi, Somayeh Hamde Qaddareh
      We proposed an amplified FRET immunosensing for detection of CA15-3 tumor marker by highly biospecific interactions between CA 15–3 antigen and the corresponding antibody and aptamer. In this sandwich type immunoassay, CA15-3 antibody-functionalized carbon dots and AuNPs labeled PAMAM-Dendrimer/aptamer were used as donor/acceptor, respectively. When CA 15-3 Ag was added to homogenous immunoassay, the strong complex interaction between CA15-3 Ab-CA15-3 Ag- aptamer caused in more coming closer carbon dot and AuNPs and more decreasing fluorescence signal. The decreased fluorescence intensity was linear at three ranges including in concentration range 1.1 μUmL−1 to 16 μU mL−1 with regression of R2 = 0.9879, at the concentration range 16 μU mL−1 to 0.163 mU mL−1 with regression of R2 = 0.9944 and at the concentration range 0.163 mU mL−1 to 5.0 mU mL−1 with regression of R2 = 0.9805. The detection limit of the FRET immunoassay was 0.9 μU mL−1. In addition, this FRET immunosensing is applicable in diluted human serum. The recovery values were in the range of 95.86–96.97% for CA 15-3 Ag in spiked serum sample with RSD lower than 7.3%. The proposed immunoassay could be a valid model for establishing other immunoassays for detection of different cancer tumor markers with relevant antigens and antibodies.
      Graphical abstract image

      PubDate: 2018-06-18T10:30:57Z
  • Fabrication of glycerol biosensor based on co-immobilization of enzyme
           nanoparticles onto pencil graphite electrode
    • Abstract: Publication date: Available online 14 June 2018
      Source:Analytical Biochemistry
      Author(s): Vinay Narwal, C.S. Pundir
      Glycerol kinase (GK) and glycerol-3- phosphate oxidase (GPO) nanoparticles (NPs) were prepared, characterized and immobilized onto pencil graphite (PG) electrode to fabricate an improved amperometric glycerol biosensor (GKNPs/GPONPs/PGE). GKNPs/GPONPs/PGE worked in optimum conditions of pH 7.0, temperature 30 °C, at an applied potential of −0.3 V. The biosensor exhibited wide linear response in a concentration range of glycerol (0.01–45 mM) with detection limit 0.0001 μM. The biosensor revealed high sensitivity (7.24 μAmM−1cm−2), low response time (2.5s) and a good agreement with the standard enzymic colorimetric method with a correlation coefficient (R2 = 0.99). The evaluation study of biosensor offered a good analytical recovery of 98.73% when glycerol concentration was added to the sera sample. In addition, within and between batches study of working electrode showed coefficients of variation as 0.105% and 0.14%, respectively. The application of biosensor is performed in the serum of apparently healthy subject and patients affected by cardiogenic shock. There was a 20% loss in initial activity of biosensor after its regular use over a time period of 180 days, while being stored at 4 °C.

      PubDate: 2018-06-18T10:30:57Z
  • Identification of adeno-associated virus capsid proteins using ZipChip
    • Authors: Yun Zhang; Yan Wang; Zoran Sosic; Li Zang; Svetlana Bergelson; Wei Zhang
      Abstract: Publication date: Available online 8 June 2018
      Source:Analytical Biochemistry
      Author(s): Yun Zhang, Yan Wang, Zoran Sosic, Li Zang, Svetlana Bergelson, Wei Zhang
      A simple and rapid identity test of adeno-associated virus (AAV) serotypes is important for supporting the AAV gene therapy development, as it relates to its efficacy and safety. The current mass spectrometry-based identity tests require extensive sample preparation steps, relatively large sample quantities and long analysis time. Herein, we describe a simple and novel microfluidic ZipChip CE/MS method used to characterize AAV capsid proteins. The three capsid proteins of AAV2 were separated and identified within 4 min using 5 nL of sample directly from a polysorbate-containing formulation buffer. This rapid method can be suitable to confirm AAV serotype identity.
      Graphical abstract image

      PubDate: 2018-06-11T10:22:30Z
      DOI: 10.1016/j.ab.2018.06.006
  • Secondary structure assessment of formulated bevacizumab in the presence
           of SDS by deep ultraviolet resonance Raman (DUVRR) spectroscopy
    • Authors: Chen Qiu; Sergey Arzhantsev
      Abstract: Publication date: Available online 7 June 2018
      Source:Analytical Biochemistry
      Author(s): Chen Qiu, Sergey Arzhantsev
      A deep-ultraviolet resonance Raman (DUVRR) spectroscopic method has been used to study the secondary structural changes of a therapeutic monoclonal antibody (mAb), bevacizumab (Avastin™) under a chemical stress: the presence of sodium dodecyl sulfate (SDS). The results demonstrate that DUVRR spectroscopy can assay the higher order structure of the formulated protein in a sensitive and selective manner. The SDS-induced partially unfolding of the mAb was probed by DUVRR spectroscopy where the amide I, II and III spectral features showed conformational changes between beta-sheet, alpha-helix and random coil forms. A chemometric model was also built to analyze the spectral changes occurring with protein-SDS interactions. The analysis showed there are different stages of mAb-SDS interaction as the SDS concentration increases. In addition, a two-dimensional (2D) correlation analysis was applied to the DUVRR spectra to visualize the secondary structure changes of bevacizumab under stresses. As an addition to the chemometric model, the 2D correlation mapping method suggested different transitions between secondary structure motifs were occurring at different SDS concentrations. Overall, chemometric and 2D analysis provided complimentary information, and show the potential of coupling DUVRR with advanced statistical methods in revealing complex structural information in formulated protein pharmaceuticals.
      Graphical abstract image

      PubDate: 2018-06-08T10:09:44Z
      DOI: 10.1016/j.ab.2018.06.003
  • Coupling coumarin to gold nanoparticles by DNA chains for sensitive
           detection of DNase I
    • Authors: Yonghua Liu; Jiru Xu; Qiong Wang; Mei-Jin Li
      Abstract: Publication date: Available online 6 June 2018
      Source:Analytical Biochemistry
      Author(s): Yonghua Liu, Jiru Xu, Qiong Wang, Mei-Jin Li
      A kind of coumarin-modified gold nanoparticle by the bridge of dsDNA chains was designed and synthesized for sensitive detection of DNase I. The fluorescence of coumarin 343 at emission wavelengths of 491 nm excited at 440 nm was quenched by the gold nanoparticles due to the energy transfer process after the coumarin 343 was connected on the gold nanoparticles by DNA chains. When dsDNA chains were cut off by DNase I, the coumarin 343 molecules were released from gold nanoparticles and the fluorescence of coumarin 343 would be restored. The DNase I activity could be detected by this fluorescence assay with a high sensitivity based on the change of the energy transfer efficiency. The intensity of restored fluorescence is linearly related to the quantity of DNase I in the range from 1.0 to 40 mU/mL with a detection limit of 0.22 mU/mL. This design idea could render a useful way to develop similar molecular or enzyme sensor in analytical or biological fields.
      Graphical abstract image

      PubDate: 2018-06-08T10:09:44Z
      DOI: 10.1016/j.ab.2018.06.002
  • An impedimetric micro-immunosensing assay to detect Alzheimer's disease
           biomarker: Aβ40
    • Authors: Norazreen Zakaria; Muhammad Zaki Ramli; Kalavathy Ramasamy; Lim Siong Meng; Chan Yean Yean; Kirnpal Kaur Banga Singh; Zainiharyati Mohd Zain; Kim-Fatt Low
      Abstract: Publication date: Available online 4 June 2018
      Source:Analytical Biochemistry
      Author(s): Norazreen Zakaria, Muhammad Zaki Ramli, Kalavathy Ramasamy, Lim Siong Meng, Chan Yean Yean, Kirnpal Kaur Banga Singh, Zainiharyati Mohd Zain, Kim-Fatt Low
      A miniaturized biosensing platform, based on monoclonal amyloid-beta antibodies (mAβab) that were immobilized on a disc-shaped platinum/iridium (Pt/Ir) microelectrode surface coupled with an impedimetric signal transducer, was developed for the label-free and sensitive detection of amyloid-beta peptide fragment 1–40 (Aβ40); a reliable biomarker for early diagnosis of Alzheimer's disease (AD). A Pt/Ir microelectrode was electropolymerized with poly (ortho-phenylenediamine), a conducting free amine-containing aromatic polymer; followed by crosslinking with glutaraldehyde for subsequent coupling of mAβab on the microelectrode surface. This modification strategy efficiently improved the impedimetric detection performance of Aβ40 in terms of charge transfer resistance (∼400-fold difference) and normalized impedance magnitude percentage change (∼40% increase) compared with a passive adsorption-based immobilization method. The sensitivity of the micro-immunosensing assay was found to be 1056 kΩ/(pg/mL)/cm2 and the limit of detection was found to be 4.81 pg/mL with a dynamic range of 1−104 pg/mL (R2 = 0.9932). The overall precision of the assay, as measured by relative standard deviation, ranged from 0.84 to 5.15%, demonstrating its reliability and accuracy; while in respect to assay durability and stability, the immobilized mAβab were able to maintain 80% of their binding activity to Aβ40 after incubation for 48 h at ambient temperature (25 °C). To validate the practical applicability, the assay was tested using brain tissue lysates prepared from AD-induced rats. Results indicate that the proposed impedimetric micro-immunosensing platform is highly versatile and adaptable for the quantitative detection of other disease-related biomarkers.

      PubDate: 2018-06-05T10:01:05Z
      DOI: 10.1016/j.ab.2018.05.031
  • Analysis of the microbial cell-Ab binding in buffer solution by the
           piezoelectric resonator
    • Authors: O.I. Guliy; B.D. Zaitsev; I.A. Borodina; G.L. Burygin; O.A. Karavaeva; A.P. Semyonov
      Abstract: Publication date: Available online 2 June 2018
      Source:Analytical Biochemistry
      Author(s): O.I. Guliy, B.D. Zaitsev, I.A. Borodina, G.L. Burygin, O.A. Karavaeva, A.P. Semyonov
      The possibility of the registration of the interaction of the cells A. lipoferum Sp59b with the specific antibodies directly in the conducting suspensions by using an acoustic sensor was shown. The main element of the sensor is a piezoelectric resonator with a lateral electric field. The analysis is based on a comparison of the resonator's electrical impedance before and after the specific biological interaction between the cells and antibodies. By using this sensor one can detect and identify the bacterial cells directly in the buffer solution with the conductivity between 2.4 and 20 μS/cm. The minimum detectable concentration of the bacterial cells turned out to be ∼103 cells/ml and for a short time (less than 10 min). Also the possibility of the detection of the cells in the presence of the extraneous microflora was shown. The results provide the opportunities for the development of a new class of the methods for the analysis of the microbial cells in real-time directly in the buffer solution.

      PubDate: 2018-06-05T10:01:05Z
      DOI: 10.1016/j.ab.2018.05.028
  • Analysis of new charge-neutral DNA/RNA analogues phosphoryl guanidine
           oligonucleotides (PGO) by gel electrophoresis
    • Authors: Alesya Fokina; Meiling Wang; Anna Ilyina; Kristina Klabenkova; Ekaterina Burakova; Boris Chelobanov; Dmitry Stetsenko
      Abstract: Publication date: Available online 2 June 2018
      Source:Analytical Biochemistry
      Author(s): Alesya Fokina, Meiling Wang, Anna Ilyina, Kristina Klabenkova, Ekaterina Burakova, Boris Chelobanov, Dmitry Stetsenko
      Analysis and isolation of new charge-neutral phosphoryl guanidine oligonucleotides (PGO) by vertical slab electrophoresis were tested at different pH values (3–11) or in the presence of SDS as a micelle-forming agent. The most convenient way to analyze and purify phosphoryl guanidine oligonucleotides was by denaturing PAGE (8 M urea) at pH 3. The mobility of PGO is dependent on their A + C content. To analyze PGO containing only G, T or U, denaturing PAGE at pH 11 can be used, although the conditions need to be optimized. Bands were visualized by UV shadowing or Coomassie Brilliant Blue staining.

      PubDate: 2018-06-02T09:56:32Z
      DOI: 10.1016/j.ab.2018.05.027
  • Carbon nanotube-based aptasensor for sensitive electrochemical detection
           of whole-cell Salmonella
    • Authors: Md Rakibul Hasan; Thiruchelvi Pulingam; Jimmy Nelson Appaturi; Anis Nadyra Zifruddin; Swe Jyan Teh; Teck Wei Lim; Fatimah Ibrahim; Bey Fen Leo; Kwai Lin Thong
      Abstract: Publication date: Available online 2 June 2018
      Source:Analytical Biochemistry
      Author(s): Md Rakibul Hasan, Thiruchelvi Pulingam, Jimmy Nelson Appaturi, Anis Nadyra Zifruddin, Swe Jyan Teh, Teck Wei Lim, Fatimah Ibrahim, Bey Fen Leo, Kwai Lin Thong
      In this study, an amino-modified aptasensor using multi-walled carbon nanotubes (MWCNTs)-deposited ITO electrode was prepared and evaluated for the detection of pathogenic Salmonella bacteria. An amino-modified aptamer (ssDNA) which binds selectively to whole-cell Salmonella was immobilised on the COOH-rich MWCNTs to produce the ssDNA/MWCNT/ITO electrode. The morphology of the MWCNT before and after interaction with the aptamers were observed using scanning electron microscopy (SEM). Cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to investigate the electrochemical properties and conductivity of the aptasensor. The results showed that the impedance measured at the ssDNA/MWCNT/ITO electrode surface increased after exposure to Salmonella cells, which indicated successful binding of Salmonella on the aptamer-functionalised surface. The developed ssDNA/MWCNT/ITO aptasensor was stable and maintained linearity when the scan rate was increased from 10 mV s−1 to 90 mV s−1. The detection limit of the ssDNA/MWCNT/ITO aptasensor, determined from the sensitivity analysis, was found to be 5.5 × 101 cfu mL−1 and 6.7 × 101 cfu mL−1 for S. Enteritidis and S. Typhimurium, respectively. The specificity test demonstrated that Salmonella bound specifically to the ssDNA/MWCNT/ITO aptasensor surface, when compared with non-Salmonella spp. The prepared aptasensor was successfully applied for the detection of Salmonella in food samples.
      Graphical abstract image

      PubDate: 2018-06-02T09:56:32Z
      DOI: 10.1016/j.ab.2018.06.001
  • A novel approach for amine derivatization of MoS2 nanosheets and their
           application toward label-free immunosensor
    • Authors: Manil Kukkar; Satish K. Tuteja; Parveen Kumar; Ki-Hyun Kim; Akhshay Singh Bhadwal; Akash Deep
      Abstract: Publication date: Available online 31 May 2018
      Source:Analytical Biochemistry
      Author(s): Manil Kukkar, Satish K. Tuteja, Parveen Kumar, Ki-Hyun Kim, Akhshay Singh Bhadwal, Akash Deep
      The application of molybdenum disulfide (MoS2) nanosheets has assumed great significance in the design of next-generation biosensors. The immobilization of biomolecules on MoS2 nanosheets has generally been achieved via hydrophobic interactions or through other complicated surface modifications. In this work, we report a novel strategy for the electrochemical amine derivatization of MoS2 nanosheets. This newly proposed approach facilitates immobilization of the MoS2 nanosheets with antibodies via facile EDC/NHS {N-(3-dimethylaminopropyl)-N-ethylcarbodiimide/N-hydroxysuccinimide)} cross-linking chemistry. To this end, the MoS2 nanosheets were first exfoliated and then electrochemically modified with 2-aminobenzylamine which anchored onto the MoS2's surface via pi-stacking. A subsequent bioconjugation of the above amine-derivatized MoS2 nanosheets with anti-prostate-specific antigen (PSA) antibodies has realized an immunosensing device for the detection of the ‘prostate specific antigen’. The application of the proposed immunosensor was characterized with a low detection limit (10−3 ng/mL) over a very wide quantitation range (10−3 to 200 ng/mL).

      PubDate: 2018-06-02T09:56:32Z
      DOI: 10.1016/j.ab.2018.05.029
  • A competitive aptamer chemiluminescence assay for ochratoxin A using a
           single silica photonic crystal microsphere
    • Authors: Peng Shen; Wei Li; Zhi Ding; Yang Deng; Yan Liu; Xuerui Zhu; Tingting Cai; Jianlin Li; Tiesong Zheng
      Abstract: Publication date: Available online 31 May 2018
      Source:Analytical Biochemistry
      Author(s): Peng Shen, Wei Li, Zhi Ding, Yang Deng, Yan Liu, Xuerui Zhu, Tingting Cai, Jianlin Li, Tiesong Zheng
      We designed a competitive aptamer chemiluminescence assay for ochratoxin A (OTA) on the surface of a single silica photonic crystal microsphere (SPCM) in cereal samples. The structural color of SPCMs is used to recognize and trace the microspheres during process of detection. Anti-aptamer was immobilized on the surface of SPCM. OTA and anti-aptamer competed to bind to aptamer when OTA and its aptamer (labeled by biotin at 5′end) were added in the system. The chemiluminescence signal was developed by the horseradish peroxidase (HRP), luminol and H2O2. The molecules on the single SPCM can produce enough chemiluminescence signal intensity for quantitative detection for OTA. The linear detection range for OTA was from 1 pg/mL to 1 ng/mL and recovery rates were 89%–95%, 81%–92% and 94%–105% in rice, wheat and corn, respectively. The results showed that the developed method for OTA using a single SPCM has a great application potential in cereal samples.

      PubDate: 2018-06-02T09:56:32Z
      DOI: 10.1016/j.ab.2018.05.025
  • A target-triggered biosensing platform for detection of HBV DNA based on
           DNA walker and CHA
    • Authors: Feng Tao; Jie Fang Yongcan Guo Yiyi Tao Xinle Han
      Abstract: Publication date: Available online 30 May 2018
      Source:Analytical Biochemistry
      Author(s): Feng Tao, Jie Fang, Yongcan Guo, Yiyi Tao, Xinle Han, Yuxin Hu, Jinjing Wang, Luyuan Li, Yulin Jian, Guoming Xie
      Hepatitis B virus (HBV), one of the causative agents of viral hepatitis, may lead to chronic hepatitis, cirrhosis, and liver cancer. In this work, we designed a sensitive and modular biosensing platform for detecting HBV DNA based on a DNA walker that hangs on to surfaces and a catalyst-triggered catalyzed hairpin assembly (CHA). In the presence of HBV DNA, strand displacement reaction between target and double-stranded complex caused the release of walker strand to trigger the DNA walker. Then, a catalyst was free to open the trapped hairpins to form a new double-strand complex, driving the CHA reaction. Thus, a powerful cascade amplification reaction realized in DNA walker and CHA based on toehold-mediated strand displacement reaction in this system. To achieve quantitative detection of HBV DNA, a fluorescent-quencher signaling pair was employed, the turn-on fluorescence provided an analytical signal. A wide detection range from 0.5 nM to 50 nM with a detection limit as low as 0.20 nM was reached on the condition of acceptable specificity and reproducibility. We could also further apply it to multiple different bioanalysis by changing adjustable elements. This reported biosensor opened a new avenue for sensitivity and modularity of DNA detection.
      Graphical abstract image

      PubDate: 2018-05-30T09:45:58Z
  • Au nanoparticles-ZnO composite nanotubes using natural silk fibroin fiber
           as template for electrochemical non-enzymatic sensing of hydrogen peroxide
    • Authors: Liangliang Chen; Xiaolong Feng Cui Qianying Qiu Xiaojun Chen Jinzhong
      Abstract: Publication date: 1 August 2018
      Source:Analytical Biochemistry, Volume 554
      Author(s): Liangliang Chen, Xiaolong Xu, Feng Cui, Qianying Qiu, Xiaojun Chen, Jinzhong Xu
      A novel electrochemical sensor based on the composite of gold nanoparticles/zinc oxide nanotube (AuNPs/ZnO-NTs) was constructed and its application as hydrogen peroxide (H2O2) non-enzymatic sensor was investigated. ZnO-NTs were prepared by a biomineralization strategy in which silk fibroin fiber (SFF) was used as template, and thus the ZnO-NTs inherited the advantages of SFF such as mechanical stability, flexible biomimetic morphology and biocompatibility. The AuNPs/ZnO-NTs was further prepared by the electrostatic absorption of AuNPs onto the surface of ZnO-NTs, and found to be capable to catalyze the reduction of H2O2. The working potential was 0.05 V, which was far higher than those in literatures, indicating the strong anti-interference ability in the real application. The catalytic current was linearly proportional in the concentration range of 1 μM–3.0 mM with a sensitivity of 1336.7 μA mM−1 cm−2. The detection limit was estimated to be 0.1 μM (S/N = 3). Such a high sensitivity was attributed to the electrocatalytic property of ZnO and high electron transfer ability of AuNPs/ZnO-NTs structure. Moreover, the final detection results of H2O2 in real samples showed the acceptable accuracy compared with the traditional potassium permanganate titration, exhibiting the prospect to be used as an applicable sensor in actual detections.

      PubDate: 2018-05-28T13:20:12Z
  • Molecularly imprinted polymer based microtiter chemiluminescence array for
           determination of phenothiazines and benzodiazepines in pork
    • Authors: Wan Qiu; Xia Jun Huang Geng Nan Wang Jing Liu
      Abstract: Publication date: Available online 25 May 2018
      Source:Analytical Biochemistry
      Author(s): Wan Qiu Xia, Jun Huang, Geng Nan Wang, Jing Liu, Jian Ping Wang
      In this study, a molecularly imprinted polymer based chemiluminescence array capable of simultaneous determining phenothiazines and benzodiazepines was first reported. Two polymers were coated in different wells of the conventional 96-well microtiter plate as the recognition reagents, and the added analytes competed with a horseradish peroxidase-labeled bi-hapten conjugate to bind the recognition reagents. The light signal was induced by using a highly effective luminol-H2O2-IMP system. The assay procedure consisted of only one sample-loading step prior to data acquisition. Then, the array was used to determine 4 phenothiazines and 5 benzodiazepines in pork simultaneously. The limits of detection for the 9 drugs were in a range of 0.001–0.01 ng/mL, and the recoveries from the fortified blank pork were in a range of 63.5%–94.1%. Furthermore, the array could be reused for 8 times. The detection results for some real pork samples were consistent with an ultra performance liquid chromatography method.
      Graphical abstract image

      PubDate: 2018-05-28T13:20:12Z
  • Advanced tools for the analysis of protein phosphorylation in yeast
    • Authors: Corvin Walter; Humberto Gonczarowska-Jorge Albert Sickmann Zahedi Chris Meisinger Oliver
      Abstract: Publication date: Available online 24 May 2018
      Source:Analytical Biochemistry
      Author(s): Corvin Walter, Humberto Gonczarowska-Jorge, Albert Sickmann, René P. Zahedi, Chris Meisinger, Oliver Schmidt
      The biochemical analysis of protein phosphorylation in mitochondria lags behind that of cytosolic signaling events. One reason is the poor stability of many phosphorylation sites during common isolation procedures for mitochondria. We present here an optimized, fast protocol for the purification of yeast mitochondria that greatly increases recovery of phosphorylated mitochondrial proteins. Moreover, we describe improved protocols for the biochemical analysis of mitochondrial protein phosphorylation by Zn2+-Phos-tag electrophoresis under both denaturing and - for the first time - native conditions, and demonstrate that they outperform previously applied methods.

      PubDate: 2018-05-28T13:20:12Z
  • A simple electrochemical method to monitor an azo dye reaction with a
           liver protein
    • Authors: Elsa Maria; Reinaldo Marchetto Angela Regina Araujo Jaime Vega-Chacon Maria
      Abstract: Publication date: Available online 23 May 2018
      Source:Analytical Biochemistry
      Author(s): Elsa Maria Materón, Reinaldo Marchetto, Angela Regina Araujo, Jaime Vega-Chacon, Maria I. Pividori, Miguel Jafelicci, Flavio M. Shimizu, Osvaldo N. Oliveira, Maria Valnice Boldrin Zanoni
      Disperse Orange 37 (DO37) is an efficient azo dye for dyeing synthetic textile materials owing to its resistance to degradation that may also be harmful to humans as DO37 is not entirely eliminated in wastewater treatment. In this paper, we demonstrate that DO37 is bleached by reduced glutathione (GSH) in a reaction catalyzed by glutathione-s-transferase (GST), a phase II detoxification enzyme. The reaction included a nucleophilic attack involving sulfhydryl groups, confirmed using density functional theory (DFT) calculations. DO37 also induced quenching in the fluorescence of GST through static suppression. The reaction was determined using differential pulse voltammetry (DPV) by monitoring the oxidation peak at 0.65 V of GSH sulfhydryl group. Quantitative estimation of the product reaction could be made by measuring an additional oxidation peak at 0.91 V which increased linearly with DO37 concentration. These electrochemical determinations were made possible by preconcentrating the reaction product on a graphite-epoxy electrode with immobilization of GST onto magnetite nanoparticles. Straightforward biological implications from the results are associated with the known toxicity of azo dyes such as DO37, which has been proven here to interact strongly with both GSH and the liver enzyme GST, and may induce hepatocarcinogenesis or other types of cancer.
      Graphical abstract image

      PubDate: 2018-05-28T13:20:12Z
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