Two-dimensional electrophoresis on a microfluidic chip for quantitative amino acid analysis

Anal Bioanal Chem. 2009 Aug;394(7):1911-7. doi: 10.1007/s00216-009-2860-3. Epub 2009 Jun 7.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / analysis*
  • Electrophoresis, Gel, Two-Dimensional / instrumentation
  • Electrophoresis, Gel, Two-Dimensional / methods
  • Fluorescence
  • Hydrogen-Ion Concentration
  • Light
  • Mercury
  • Microfluidic Analytical Techniques / instrumentation
  • Microfluidic Analytical Techniques / methods*
  • Sensitivity and Specificity
  • Sodium Dodecyl Sulfate / chemistry
  • Time Factors

Substances

  • Amino Acids
  • Sodium Dodecyl Sulfate
  • Mercury