Skip to content Skip to navigation menu


SKU Number : M1091

For the isolation of Listeria monocytogenes

Information : This product cannot be returned.

To Display Prices, you must be logged in

Peptones and beef heart digest provide nitrogen, carbon, amino acids and vitamins. Agar is the solidifying agent. Sodium chloride maintains the osmotic balance. Ferric ammonium citrate aids in the differentiation of Listeria spp.

Since all Listeria spp. hydrolyze esculin, the addition of ferric ions to the medium will detect the reaction. A blackening of the colony and surrounding medium in cultures containing esculin-hydrolyzing bacteria results from the formation of 6,7-dihydroxycoumarin which reacts with the ferric ions.

Selectivity is provided by the presence of lithium chloride in the formula. The high salt tolerance of Listeria is used as a means to markedly inhibit growth of enterococci. Selectivity is increased by addition of Moxalactam and Colistin sulfate to the base.