application： Used as a pharmaceutical intermediate to reduce toxicity and as an enzyme substrate in diagnostic reagents. Salmon-gal is used in conjunction with IPTG for detection of β-galactosidase activity in bacterial colonies in a colometric assay to detect recombinants (white) from the non-recombinants (SALMON). In conjunction with X-glu, salmon-gal is useful for simultaneous detection of GUS and Lac activities on the same plate.