Microfabricated flow chamber for fluorescence-based chemistries and stopped-flow injection cytometry

Area of Science:

• Analytical Chemistry
• Biotechnology
• Microfluidics

Background:

• Fluorimetric assays require precise sample and reagent handling.
• Traditional flow cytometry methods offer high resolution but can be complex.
• Flow injection analysis (FIA) provides automated sample processing.

Purpose of the Study:

• To introduce a microfabricated flow chamber (MFC) system for liquid-based fluorimetric assays.
• To combine FIA with sheath flow principles for enhanced mixing and analysis.
• To demonstrate the system's applicability in bioanalytical and cytometric studies.

Main Methods:

• Development of a microfabricated flow chamber (MFC).
• Integration with a double-syringe-pump flow injection analysis (FIA) apparatus.
• Incorporation of 'sheath flow' technique and stopped-flow FIA for reproducible mixing.
• Demonstration using an enzymatic assay for Savinase activity determination.
• Coupling with a fluorescence microscope for quantitative analysis.

Main Results:

• The FIA-MFC system achieved high injection reproducibility (1.5%).
• Demonstrated excellent linearity of response (r2 = 0.9997) across relevant activity ranges.
• Successfully quantified the reaction product of an enzymatic assay.
• Validated the system's suitability for bioanalytical applications.

Conclusions:

• The developed FIA-MFC system offers a robust platform for sensitive fluorimetric assays.
• The integration of FIA and sheath flow principles enhances reproducibility and analytical performance.
• This system is a valuable tool for quantitative bioanalysis and cytometric studies.