Description 

Laurylsulfate-tryptose broth is a selective enrichment media used for the detection and enumeration of escherichia coli and coliforms in water and food products.  

The medium was formulated by malmann and darby who showed, in 1941, that sodium laurylsulfate was the best selective agent among a number of surfactants and did not inhibit the growth of coliform bacteria. levine later showed that the medium reduced the number of false positives by inhibiting the growth of sporulated gas-producing bacteria.

Typical composition   

The composition can be adjusted in order to obtain optimal performance.   

for 1 liter of media (single strength) :

- tryptose ......................................................................................... 20,00 g

- lactose ............................................................................................ 5,00 g

- di-potassium phosphate .................................................................... 2,75 g

- sodium monopotassium phosphate .................................................... 5,00 g

- sodium laurylsulfate ........................................................................ 0,10 g 

ph of the ready-to-use media at 25 °c : 6,8 ± 0,2. 

Packaging   

Dehydrated media :

500 g bottle  ................................................................................  BK010HA 

ready-to-use media each containing a durham tube.

50 x 10 ml tubes (simple concentration)                BM09708

50 x 10 ml (double strength)                                BM09808 

SELECTIVE ENRICHMENT OF ESCHERICHIA COLI AND OTHER COLIFORMS