Characterizing microfluidic approaches for a fast and efficient reagent exchange in single-molecule studies

Area of Science:

• Biophysics
• Microfluidics
• Biochemistry

Background:

• Single-molecule experiments commonly utilize flow cells for liquid environments and reagent exchange.
• Current methods using syringe pumps face challenges with high flow rates disturbing systems or low flow rates causing reagent gradients.
• Precise single-molecule measurements demand rapid reagent exchange and minimal diffusion.

Purpose of the Study:

• To introduce a novel multistream laminar microfluidic flow cell for enhanced single-molecule experiments.
• To achieve significantly faster fluid switching times compared to conventional flow cells.
• To establish a predictive model for fluid switching behavior in microfluidic devices.

Main Methods:

• Implementation of a multistream laminar microfluidic cell with two inlets and one outlet.
• Characterization of fluid dynamics and switching times within the microfluidic cell.
• Development of a phenomenological expression to predict boundary switching time.

Main Results:

• The proposed microfluidic flow cell achieved a minimum fluid switching time of 0.25 seconds.
• A phenomenological expression was defined to predict boundary switching times based on flow cell geometry.
• The platform demonstrated potential for studying single-molecule kinetics.

Conclusions:

• The developed microfluidic flow cell significantly improves reagent exchange speed and reduces diffusion in single-molecule experiments.
• The predictive model aids in designing microfluidic devices for specific kinetic studies.
• This technology offers a promising platform for advancing single-molecule biophysical and biochemical research.