Petri dish with agar 15336S

Plate Count Agar + Neutralizing is a prepared plated medium used for detection and enumeration of bacteria in surfaces testing and air microbial control by dynamic sampling technique. The composition of the base culture medium complies with the specifications given by the American Public Health Association and ISO 4833 with the addition of neutralizing agents, which are included in the medium to inactivate residual disinfectants allowing detection of microorganisms surviving after treatment of surface and material with antiseptics. This medium is also available as gamma-irradiated triple-bagged plates, particularly suitable for use in restricted areas like isolators and clean rooms. TYPICAL FORMULA* (Per litre of Purified Water) Enzymatic Digest of Casein 5.0 g Yeast Extract 2.5 g Glucose 1.0 g Agar 15.0 g Histidine 1.0 g Lecithin 0.7 g Polysorbate 80 5.0 ml Sodium Thiosulfate 0.5 g METHOD PRINCIPLE Enzymatic digest of casein provides amino acids, nitrogen, carbon, vitamins and other nutrients which support the growth of microorganisms. Yeast extract is a source of vitamins, particularly of B-group. Glucose is the fermentable carbohydrate. Agar is the solidifying agent. Histidine inactivates aldehydes. Lecithin neutralizes quaternary ammonium compounds. Polysorbate 80 (Tween 80) is effective against phenolic compounds and mercurial derivates. Sodium thiosulfate neutralizes halogen compounds. TEST PROCEDURE For Active Air Sampling, place the plate, lid up, in the air sampler, remove the lid of the plate and sample a specific volume of air according to laboratory procedure.