High-throughput microfluidics: improved sample treatment and washing over standard wells

Fluid flow in microchannels is used to treat or wash samples and can be incorporated into high-throughput applications such as drug screening, which currently use standard microtiter wells for performing assays. This paper provides theoretical and experimental data comparing microchannels and standard wells on the metrics of sample washing and experimental error in treatment concentrations. It is shown numerically and experimentally that microchannel concentration can be approximated with an inverse linear relationship to input volume. The experimentally supported mathematical approximation and error propagation methods are used to compare the accuracy and precision of treatments in microchannels vs. standard wells. Mathematical results suggest microchannels can provide 10 or more times the treatment precision of standard wells for volume ratios typical of high-throughput screening. Passive-pumping and diffusion are utilized to improve microchannel accuracy and precision even further in a treat-wait-treat method. The advantages of microchannels outlined here can have large-scale effects on cost and accuracy in screening applications.