(240i) Development of a Microfluidics-Based Gel Protein Recovery System

A polymethylmethacrylate (PMMA) microfluidic chip, in which fluid is manipulated to transport protein from a polyacrylamide gel electrophoresis (PAGE) gel piece to a collection reservoir via a microfluidic channel, has been developed. The protein sample is mobilized out of the gel (loaded in a chip access hole) into a low electroosmotic flow capillary electrophoresis (CE) microfluidic channel under the influence of an electric field. Simultaneously, hydrostatic pressure from the filled buffer reservoirs is used to direct the protein sample to a third reservoir, through a field-free channel connected to the electrophoresis channel. Using this novel process of protein transport from a gel sample, proteins from coomassie-stained gels have been transferred into solution in 15-30 min, with good sample recovery, using a run buffer containing an anionic acid labile surfactant. A variety of small and medium-sized proteins were successfully recovered and detected using both electrospray and MALDI mass spectrometry over gel loads of 0.1 -10 µg. This technological tool is very important for extracting quality intact protein samples from polyacrylamide gels, from which accurate protein molecular weights and protein sequences can be obtained using intact molecules.