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The principle use for this product is in the testing of disinfectants and antiseptics. In 1989, the European Committee for Standardisation (CEN) set up a technical committee to produce harmonised test methods for disinfectants and antiseptics. The CEN standards provide a useful basis for disinfectant validation, and although alternative methods could be used for assessing disinfectant efficacy, following the same basic methods allows not only direct comparison between products but also comparison across various different laboratories. The adaptability of the methods - numerous validation studies based on the CEN methods have been accepted by both the European and US regulatory authorities - allows end- users to customise the methods to their specific requirements. Lecithin and polysorbate 80 (Tween 80) inactivate surface disinfectants (lecithin neutralises quaternary ammonium compounds and Tween 80 neutralises phenols, formalin, hexachlorophene and in combination with the lecithin ethanol). L-histidine, in combination with lecithin and Tween 80, neutralises aldehydes and formaldehyde generating agents. Sodium thiosulphate neutralises iodine and chlorine. -
Malt Extract Agar is a medium for the isolation of many yeasts and moulds. The low pH inhibits most bacteria and further selectivity can be achieved by lowering the pH even more by adding lactic acid to the molten cooled, medium. This formulation is customer specific with a request for an additional 5g/L of agar from the customer. It should be noted that excess heating of the medium could result in hydrolysis of the agar resulting in softening of the agar.
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Malt Extract Agar (pH 5.6) is recommended for the detection and isolation and enumeration of yeasts and moulds (1). The medium is also used in the testing of foods and various materials and for the cultivation of the strains for microbiological vitamin assays. Malt Extract Agar (pH 5.6) has been used to cultivate fungi and yeast cultures in the sugar industry, in the manufacturing of syrups, soft drinks, and foods.
This medium meets the requirements of The British Standards Institution (2).
References- Galloway, L. and Burgess, R. (1952) Applied Mycology and Bacteriology, Leonard Hill, London. Thom and Church, 1926. The Aspergilli.
- The British Standards Institution (2015) BS EN 16615:2015 Chemical disinfectants and antiseptics. Quantitative test method for the evaluation of bactericidal and yeasticidal activity on non-porous surfaces with mechanical action employing wipes in the medical area (4- field test). Test method and requirements (phase 2, step 2). Published by BSI Standards Limited.
