Complementing this medium is Lab M's Egg Yolk Tellurite, produced using the finest raw materials. As with Lab M's traditional Baird-Parker medium, the ISO formulation can be used with either Egg Yolk Tellurite or Rabbit Plasma Fibrinogen (RPF).
When the medium is used with Egg Yolk Tellurite, presumptive
S. aureus appear as black colonies demonstrating lecithinase activity as an opaque zone around the colony, encircled by a zone of clearing that is the result of lipase activity. Coagulase (RPF media) or latex agglutination tests are used for confirmation.
Where Rabbit Plasma Fibrinogen is used, typical
S. aureus appear as black colonies surrounded by a zone of precipitation, indicating coagulase activity. This is the recognised gold standard method for the identification of
S.aureus. RPF overcomes any issues with atypical colony forms and also means that further confirmatory tests are not necessary.
To find out more about Lab M's complete range of ISO media visit
www.labm.com