An improved protocol for better detection of protein using 8-anilino-1-naphthalenesulfonate

This study describes the optimum conditions at the staining time and the signal intensity for using 8-anilino-1-naphthalenesulfonate (ANS) as a fluorescent probe to detect proteins in SDS-PAGE. Using the optimized protocol, protein can be easily detected by short time fixing (20 min) and washing (2 × 5 min), followed by 10 min of staining. As low as 1-2 ng of the protein band can be detected, approximately thirty-fold higher than that of the original protocol. Furthermore, the compatibility of the staining method with MS was also explored by comparing the peptide mass fingerprinting results data of serial dilutions of BSA and ovalbumin stained by ANS with SYPRO Ruby.