Microfluidic three-dimensional hydrodynamic flow focusing for the rapid protein concentration analysis

Sungmin Hong, Pei Hsiang Tsou, Chao Kai Chou, Hirohito Yamaguchi, Chin B. Su, Mien Chie Hung, Jun Kameoka*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


A simple microfluidic 3D hydrodynamic flow focusing device has been developed and demonstrated quantitative determinations of quantum dot 525 with antibody (QD525-antibody) and hemagglutinin epitope tagged MAX (HA-MAX) protein concentrations. This device had a step depth cross junction structure at a hydrodynamic flow focusing point at which the analyte stream was flowed into a main detection channel and pinched not only horizontally but also vertically by two sheath streams. As a result, a triangular cross-sectional flow profile of the analyte stream was formed and the laser was focused on the top of the triangular shaped analyte stream. Since the detection volume was smaller than the radius of laser spot, a photon burst histogram showed Gaussian distribution, which was necessary for the quantitative analysis of protein concentration. By using this approach, a linear concentration curve of QD525-antibody down to 10 pM was demonstrated. In addition, the concentration of HA-MAX protein in HEK293 cell lysate was determined as 0.283 ± 0.015 nM. This approach requires for only 1 min determining protein concentration. As the best of our knowledge, this is the first time to determinate protein concentration by using single molecule detection techniques.

Original languageEnglish
Article number024132
Issue number2
Publication statusPublished - 2012 Apr 26
Externally publishedYes

ASJC Scopus subject areas

  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics
  • Fluid Flow and Transfer Processes
  • Colloid and Surface Chemistry


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