Single molecule and cell manipulation in soft microfluidic devices

Summary form only given as follows: We have been using soft lithography to make microfluidic chips for ultrasensitive analysis of single DNA molecules and cells. There are numerous advantages to fabricating chips out of polymeric materials, and as a result we have been able to rapidly and inexpensively fabricate active devices with moving parts, such as pinch valves and peristaltic pumps. We have also developed a microfabricated flow cytometry chip as a replacement for analytical pulsed field gel electrophoresis. Assays with these chips are two orders of magnitude faster than pulsed field gels and use a million times less material. Because they are detecting single molecules, their sensitivity is comparable to PCR based techniques. We have also developed a microfabricated fluorescence activated cell sorter and demonstrated its use in screening bacterial cells. The novel valve and pump components for on-chip fluidic manipulation that we developed in the course of this research will be useful for fabricating more complex chip designs for a variety of biotechnological applications.