On-chip sample preparation using a ChipFilter coupled to NanoLC-MS/MS for bottom-up proteomics

Sample preparation is a crucial step in bottom-up proteomics. Analytical performances of bottom-up proteomics can be improved by the miniaturization of sample preparation steps. Many microfluidic devices are proposed in the field of proteomics. But many of them are not capable of handling complex sample and do not integrate the processing and digestion steps. We propose a ChipFilter Proteolysis (CFP) microfluidic device derived from the Filter Aided Sample Preparation FASP method for the miniaturization of protein processing and digestion steps in bottom-up proteomics. The microchip has two reaction chambers of 0.6 µL volume separated by a protein filtration membrane in regenerated cellulose. Cell lysis, protein concentration and rapid chemical and enzymatic treatment can be performed in our microfluidic device. Complex proteomic samples like yeast protein extract have already been analyzed with our microchip. Compared to the traditional FASP method, our microfluidic device offers a better proteome coverage with ten times less starting material and eight times quicker protocol.