The base medium is a modification of King´s medium A which uses magnesium and potassium salts to enhance production of the pigments pyocyanin (green) and fluorescein (detected by U.V./blue light).
The medium is made selective for Pseudomonas aeruginosa by the
addition of X107 C.N. supplement. Alternatively the medium can be made selective for Pseudomonas species generally by the addition of
X108 C.F.C. supplement. This medium can be made selective for the isolation of Burkholderia cepacia by the addition of X140.