This medium is used as seed layer medium for assaying the products containing Polymyxin B, also for assaying Carbenicillin, Colistin and Colistimethate Sodium.
- Appearance: Cream to yellow homogeneous free flowing powder
- Gelling; firm, comparable with 1.2% agar gel
- Colour and clarity of prepared medium: medium amber coloured clear to slightly opalescent gel forms in petri plates
- Reaction of 4.2% w/v aqueous solution containing 1% polysorbate 80 at 25°C. pH : 7.2±0.2
- Cultural characteristics observed after an incubation at 35-37°C for 18-24 hours