Abstract: Some commercially important fish species are often substituted for by lower price species.
In order to detect fraud and to ensure that foods comply with regulations, species identification of puffer
using SDS-PAGE with Coomassie blue/silver double staining was performed. A comparison was also
made among extracts of sarcoplasmic, myofibrillar, SDS-soluble and urea-soluble proteins. The protein
concentration of SDS and urea extracts was usually higher than that of the phosphate (sarcoplasmic
and myofibrillar protein) extracts. Protein bands of low molecular weight showed the species-specific
characteristics. Identification of all tested puffers could be achieved by judging from the SDS-PAGE
patterns of the four protein extracts.