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Principle
- MF endo medium is composed of an enzymatic digest of casein, an enzymatic digest of animal tissue, soy peptone, yeast extract, lactose, sodium chloride, potassium phosphate, Dipotassium phosphate, sodium sulfite, sodium lauryl sulfate, sodium deoxycholate, and basic fuchsin.
- Enzymatic digestion of casein, enzymatic digest of animal tissue, soya peptone, and yeast extract provide nitrogen, carbon, minerals, vitamins, and trace elements to stimulate bacterial growth.
- Potassium phosphates are buffering agents. Sodium chloride maintains the osmotic balance. Lactose serves as a carbohydrate source.
- Sodium lauryl sulfate and sodium deoxycholate are selective agents used to inhibit gram-positive bacteria. Basic fuchsin is a pH indicator. Sodium sulfite is added to decolorize the basic fuchsin solution. Methanol and ethanol aid in the homogeneity of the solution and as a selective agent. Lactose is a fermentable carbohydrate.
- Lactose-positive colonies exhibit a red color caused by the aldehyde reaction with sodium sulfite and basic fuchsin. The development of a metallic sheen occurs when the organism produces aldehydes with the fermentation of lactose. Lactose non-fermenting bacteria form clear, colorless colonies.
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