Prof. Aaron Wheeler, University of Toronto

Hybrid Microfluidics for Integrated Proteomics

A common theme in chemical analyses (across a broad range of applications) is the requirement of sample processing and separations. For example, in shotgun proteomics, samples are subjected to a rigorous processing regimen (including numerous pipetting steps and reagents, as well as mixing, heating, and centrifugation) followed by two-dimensional chromatography and tandem mass spectrometry. The sample processing required for shotgun proteomics is time-consuming and tedious, and more problematically, the methodologies are not standardized, resulting in pervasive lack of reproducibility from lab to lab. In response to this challenge, we are developing a miniaturized lab-on-a-chip platform integrating and automating sample processing and separations/mass spectrometry for shotgun proteomics. In this platform, separations are implemented in the common format of microchannels, while sample processing is achieved using “digital microfluidics,” a relatively new technique in which droplets of reagents are manipulated electromechanically on an open surface. In digital microfluidics, each droplet can be individually addressed, making it a good match for implementing precise multistep reactions. Here, we present a hybrid microfluidic platform linking digital microfluidics for on-chip protein precipitation, reduction, alkylation, and enzymatic digestion and microchannels for chromatography. We anticipate that future generations of this technology will be capable of analyzing many samples in parallel, and we speculate that tools such as these will be useful for standardizing chemical analyses for shotgun proteomics and other applications.

For more information contact Prof. Facundo Fernandez (404-385-4432).