To help microbiology laboratories comply with the EU Core Directive for Quality of Water for Human Use (98/83/CE) and have confidence in reporting accurate results, the new Thermo Scientific Chromogenic Coliform Agar (CCA) (ISO) formulation is compliant with the ISO9308-1:2014 standard, cited in the Directive, and is easy to read because of the large colony size produced and vibrant coloration of the target organisms.

The ISO9308-1:2014 standard specifies a simple method for the enumeration of Escherichia coli (E. coli) and coliform bacteria that is based on membrane filtration followed by culture on a chromogenic coliform agar medium and the calculation of the number of target organisms in the sample. The method is designed for water samples with low bacterial numbers i.e. fewer than 100 total colonies, on the chromogenic coliform agar. E. coli produces dark blue to violet coloured colonies, and coliforms red to pink coloured colonies.

The medium has been quality tested in accordance with ISO11133:2014 standard, which describes the requirements for the preparation, production, storage and performance testing of culture media.

“We are delighted to provide this new ISO compliant culture medium that produces such distinctive and easy to read results,” says Simon Walker, senior director of product management and global marketing, microbiology, Thermo Fisher Scientific. “Laboratories using Thermo Scientific CCA (ISO) for testing water samples with low bacterial numbers can be confident that results will be easy to read and interpret.”

The Thermo Scientific Chromogenic Coliform Agar (ISO) is available in a choice of 500g dehydrated media packs and prepared plates in packs of ten, with a choice of 90mm and 55mm plates.