Selective medium containing mannitol and tryptose with sodium lauryl sulfate (SLS) as a selective agent. Designed for confirmation of Escherichia coli, including non‑lactose fermenters when combined with tryptophan supplementation .

Principle: Mannitol fermentation leading to gas production indicates presumptive E. coli. Growth in this medium is confirmed before further transfer to more selective media like brilliant green lactose bile broth .

Directions:

Suspend 35.60 grams in 1 Litre distilled water.

Heat if necessary to dissolve the medium completely.

Distribute into tubes containing inverted Durham’s tubes.

Sterilize by autoclaving at 15lbs pressure at 121°C for 15 minutes.

For inoculum of 1ml or less, use single strength medium.

For inocula of 10 ml or more , double strength or proportionate medium should be prepared.