Toward an integrated microchip sized 2-D polyacrylamide slab gel electrophoresis device for proteomic analysis

We describe a miniaturized instrument capable of performing 2-DE. Our miniaturized device is able to perform IEF and polyacrylamide slab gel electrophoresis (PASGE) in the same unit. It consists of a compartment for a first-dimensional IEF gel, which is connected to a second-dimensional PASGE gel. The focused samples are automatically transferred from the IEF gel to the PASGE gel by electromigration. Our preliminary experiments show that the device is able to focus and separate a mixture of proteins in approximately 1 h, excluding the time required for the staining procedure. On average, the gel-to-gel retardation factor (Rf) variation was 6.2% (+/-0.9%) and pI variation was 2.5% (+/-0.6%). Separated protein spots were excised from stained gels, digested with trypsin, and further identified by MS, thus enabling direct proteomic analysis of the separated proteins.