IMPROVED CYTOTOXICITY TESTING OF PRODUCTS IN CONTACT WITH DRINKING WATER

摘要

The Australian Water Quality Centre (AWQC) routinely conducts testing in accordance with Australian and New Zealand Standard 4020 'Testing of products for use in contact with drinking water'. Cytotoxicity testing is included as part of the Standard to determine if product extract waters exert detrimental effects against mammalian cells. In this study the MTT (-[4, 5 dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay was evaluated as a quantitative alternative to microscopy evaluation of cytotoxic results. A good correlation was obtained for analysis of product extract waters by the two methods, with the MTT assayrnproviding additional certainty for the classification of borderline cytotoxic samples. As a result of the data presented the Australian Standard was amended in 2005 (AS/NZS 4020:2005) to include the quantitative MTT assay format. Use of a new positive control, nickel nitrate, was also recommended.