Development and application of a miniaturized gel electrophoresis device for protein analysis

The present article describes a miniaturized polyacrylamide slab gel electrophoresis-chip (PASGE-Chip) that can rapidly separate a set of predefined samples as well as cell lysate samples for clinical diagnosis. The chip consists of a polymethyl methacrylate (PMMA) upper unit (25 × 30 × 10 mm, width × length × depth) with integrated buffer chambers, running electrodes and loading wells and a bottom unit comprising a silicon dioxide-coated silicon plate with embossed gel chamber (11 × 15 × 0.37 mm). This miniaturized device was designed to be fast, easy to use and cheap to produce. The polyacrylamide slab gel electrophoresis can be performed in less than 10 min with low voltage. The gel-to-gel repeatability is around 3.8%. The limit of detection is approx. 10 ng as determined by Coomassie staining of selected standard proteins, and corresponds to a 10-fold increase in sensitivity as compared with a common size PAGE analysis device (e.g. 10 × 7 cm). The device was successfully applied to peptide mass fingerprint analysis, protein sequencing and ultra-sensitive immunodetection, and the performance was compared to a commonly used regular PAGE device.