Sub-Microliter Assays and DNA Analysis on Plastic Microfluidics

Abstract

We report the design, fabrication, and performance characterization of plastic microfluidic systems for conducting (1) highly parallel enzyme-based assays using sub-microliter reagent volumes and (2) high-speed, high-resolution separation of double- and single-stranded DNA fragments for applications including genotyping and sequencing. To reduce reagent consumption, we have developed a zero-dead-volume dispensing technology for the simultaneous parallel pickup of nL volumes of 96 different reagents from a ``library plate'' and rapid delivery to a microfluidic assay card. We also demonstrate the capability to perform unlidded 200nL assays with one hour incubations. Recent DNA sequencing results are reported: up to 700 single-stranded DNA fragments are detected with single-base resolution in 40 minutes using a plastic microfluidic device with a 4-color detection system.