A Digital Microfluidic Approach to Proteomic Sample Processing

A common characteristic for proteomic analyses is the need for extensive biochemical processing. Digital microfluidics (DMF), a technique characterized by the manipulation of discrete microdroplets (100 nL−10 μL) on an open array of electrodes, is a good match for carrying out rapid, automated solution-phase reactions. Here, we report a DMF-based method integrating several common processing steps in proteomics, including reduction, alkylation, and enzymatic digestion. Fluorogenic assays were used to quantitatively evaluate the kinetics and reproducibility of each reaction step, and MALDI-MS was used for qualitative confirmation. The method is fast, facile, and reproducible, and thus has the potential to be a useful new tool in proteomics.