Casein peptone Lecithin Polysorbate Broth 500g

Description

For diluting samples of pharmaceutical, cosmetic and other raw materials or final products when determining microbial counts.

This broth complies with the recommendations of the United States Pharmacopeia XXVI (2003).

Mode of Action
The relatively high casein peptone content of this medium provides optimal conditions for the spore germination and regeneration of even damaged microorganisms.
Lecithin and polysorbate 20 inactivate many antimicrobial compounds.
KOHN et al. (1963), CHIORI et al. (1965) and HUGO and FRIER (1969) reported that soya lecithin inactivates cetrimide, chlorohexidine, chlorinated phenols, desqualinium acetate and polymyxin B. According to EVANS (1964) and BROWN (1966),
polysorbate 20 inactivates phenols, phenol derivatives, benzoic acid, p-hydroxybenzoic acid and their esters. The combination of the two can inactivate quaternary ammonium and phosphonium compounds. Thioglycollate has not been included to inactivate preservatives containing heavy metals as the thioamino acids of
the casein peptone inactivate most of these compounds and TREADWELL et al. (1958) and GIBBS (1964) have shown that thioglycollate inhibits the spores of many Bacillus and Clostridium species, especially when they are already damaged
by heat.

Typical Composition (g/litre)
Peptone from casein 20.0;
soya lecithin 5.0.
Also to be added:
polysorbate (Tween® 20) 40 ml.

Preparation
Suspend 25 g in 0.96 litre in accordance with USP, heat in a water bath set at 50 °C for about 30 minutes until completely dissolved. Add 40 ml polysorbate, autoclave (15 min at 121°C).
pH: 7.1 ± 0.2 at 25 °C.