Heipha contact agar medium detects micro-organisms in isolators


Tryptic soy contact agar inactivates residues of difficult-to-neutralise disinfectants

Biotest Group company Heipha Dr. Muller, a manufacturer of culture media for microbial diagnostics, environmental monitoring and sterility testing, has launched a culture medium that will inactivate residues of difficult-to-neutralise disinfectants to detect viable micro-organisms in isolators and cleanrooms.

The formulation of the basic medium complies with current European and US Pharmacopoeia recommendations for tryptic soy agar. To inactivate residues of disinfectants, the medium is supplemented with a mixture of active ingredients called Neutraliser A.

Environmental monitoring media are usually supplemented with lecithin, Tween 80, histidine or thiosulphate, or enzymes such as penase or cephase, to neutralise residual disinfectants, penicillins and antibiotics. Heipha ICR media makes use of these different combinations of neutralisers.

Heipha says residuals of newer generations of disinfectants using quaternary ammonium compounds and biguanides cannot be neutralised satisfactorily using these neutralisers.

The company has extensively tested its new tryptic soy contact agar with neutraliser A alongside widely used commercial disinfectants and has found that it successfully neutralises residuals of these disinfectants, where traditional neutralisers fail.

The tryptic soy contact agar with Neutraliser A – ICR+ is suitable for determining the total viable count on sanitised, dry surfaces in isolators and cleanrooms (ICR), and can be used for all hygiene monitoring purposes.

The contact plates are triple bagged and gamma-irradiated in the final packaging.

The plate model (plus or „+“) is supplied with a lockable lid. For safe transport after sampling, as well as for aerobic incubation, the plates can be locked in the “closed” position. For anaerobic or microaerophilic incubation the lid can be locked in the “vent” position.

The plates are stored at room temperature and currently have a shelf life of 3 months.