A Quantitative Microfluidic Flow Cytometer Based on Spaced Uniform Optical Field.

Area of Science:

• Biotechnology
• Analytical Chemistry
• Cell Biology

Background:

• Traditional flow cytometry is limited in quantifying intracellular or arbitrarily distributed proteins due to non-uniform illumination and lack of internal calibration standards.
• Accurate, quantitative single-cell protein analysis is crucial for biological research and clinical diagnostics.

Purpose of the Study:

• To develop a quantitative microfluidic flow cytometer capable of analyzing single-cell proteins with arbitrary spatial distributions.
• To overcome the limitations of conventional flow cytometry in protein quantification.

Main Methods:

• Utilized microfabricated metal apertures to create a uniform optical field from Gaussian beams.
• Developed a microfluidic cuvette design and validated fluorescence intensity uniformity.
• Converted multicolor fluorescence signals from antibody-binding events into absolute protein numbers.

Main Results:

• Established highly linear calibration curves across nine fluorescence channels.
• Successfully quantified five distinct fluorescent probes in a rainbow calibration microbead mixture.
• Demonstrated the ability to classify the mixture into five subpopulations based on protein levels.

Conclusions:

• The developed microfluidic flow cytometer enables accurate, quantitative analysis of single-cell proteins irrespective of their spatial distribution.
• This technology holds significant potential for advancing fundamental biological research and clinical applications at the single-cell level.