title: Two-dimensional electrophoresis on a microfluidic chip for quantitative amino acid analysis.
abstract: Analysis of complex biological samples requires the use of high-throughput analytical tools. In this work, a microfluidic two-dimensional electrophoresis system was developed with mercury-lamp-induced fluorescence detection. Mixtures of 20 standard amino acids were used to evaluate the separation performance of the system. After fluorescent labeling with fluorescein isothiocyanate, mixtures of amino acids were separated by micellar electrokinetic chromatography in the first dimension and by capillary zone electrophoresis in the second. A double electrokinetic valve system was employed for the sample injection and the switching between separation channels. Under the optimized conditions, 20 standard amino acids were effectively separated within 20 min with high resolution and repeatability. Quantitative analysis revealed linear dynamic ranges of over three orders of magnitudes with detection limits at micromolar range. To further evaluate the reliability of the system, quantitative analysis of a commercial nutrition supplement liquid was successfully demonstrated.
authors.affiliation: Key Laboratory of Biomedical Photonics of MOE, Department of Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Xu
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Feng
authors.forename: Youzhi
authors.initials: Y
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Du
authors.forename: Qingming
authors.initials: Q
authors.lastname: Luo
authors.forename: Bi-Feng
authors.initials: BF
authors.lastname: Liu
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000295:instrumentation / Q000379:methods; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D008027:Light; D008628:Mercury; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013997:Time Factors
chemical_list: D000596:Amino Acids; D012967:Sodium Dodecyl Sulfate; D008628:Mercury