A FAST AND SENSITIVE COOMASSIE BLUE STAINING FOR PROTEINS IN POLYACRYL-AMIDE GELS USING ION-PAIRING AGENT

Here we describe a fast and sensitive Coomassie blue staining method f or detection of proteins in polyacrylamide gels using an ion-pairing a gent, tetraoctylammonium bromide (TOA). To increase sensitivity, sodiu m dodecyl sulfate (SDS) in an electrophoresed gel was removed by washi ng with water for 5 min, and then the gel was stained in the mixed sol ution of 0.25% Coomassie brilliant blue R-250 (CB), and 1% TOA (mixed up at a 10 : 0.6 volume ratio). TOA inhibits the binding of CB to gel matrix by forming an ion-pair complex, thus not only increases the sta ining of CB but also helps make background destaining easy. This stain ing method reduces the staining and destaining times to 50 min and inc reases the detection limit up to 25 ng of bovine serum albumin (BSA).