Detection of tetracysteine-tagged proteins using a biarsenical fluorescein derivative through dry microplate array gel electrophoresis

The design of an extended‐run 96‐well sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) system and the development of protein detection technology based upon fluorescein derivatives that bind to peptide epitope tags, allows the creation of a truly high‐throughput analysis of protein expression, where less than 20 min are needed to separate proteins and analyze results. We demonstrate the overall capabilities of such a method combination in a complex cell lysate background, while comparing the specific results obtained using a biarsenical fluorescein‐derivative and tetracysteine epitope‐tagged proteins with total protein staining using a fluorescent gel stain and with Western blotting where an anti‐oligohistidine (His) tag antibody has been employed. When applied on purified target proteins without extraneous protein background, the demonstrated sensitivity of the assay on the extended‐run 96‐array precast SDS‐PAGE system allows detection of quantities of tagged protein as low as 1 pmol per band.