Brilliant-green Phenol-red Lactose Sucrose Agar (BPLS)
Salmonella on BPLS Agar. The colonies are red because the bacterium does not ferment lactose or sucrose.		Escherichia coli on BPLS Agar. The colonies are yellow due to the low pH which is caused by the production of acid during fermentation of lactose and/or sucrose.
This medium is used to isolate Salmonella from pathological material, foodstuffs, etc. by separating lactose- and/or sucrose-positive bacteria from lactose- and sucrose-negative bacteria. Brilliant-green in the medium inhibits accompanying micro-organisms. The picture below shows an uninoculated plate. Click to enlarge: