Status : Published (Under review)

This standard was last reviewed and confirmed in 2023. Therefore this version remains current.
This standard has been revised by ISO/CD 9308-2
Format Language
PDF
Paper
  • CHF173
Convert Swiss francs (CHF) to your currency

Abstract

ISO 9308-2:2012 specifies a method for the enumeration of E. coli and coliform bacteria in water. The method is based on the growth of target organisms in a liquid medium and calculation of the "Most Probable Number" (MPN) of organisms by reference to MPN tables. This method can be applied to all types of water, including those containing an appreciable amount of suspended matter and high background counts of heterotrophic bacteria. However it must not be used for the enumeration of coliform bacteria in marine water. When using for the enumeration of E. coli in marine waters, a 1→10 dilution in sterile water is typically required, although the method has been shown to work well with some marine waters that have a lower than normal concentration of salts. In the absence of data to support the use of the method without dilution, a 1→10 dilution is used.

This method relies upon the detection of E. coli based upon expression of the enzyme b‑D‑glucuronidase and consequently does not detect many of the enterohaemorhagic strains of E. coli, which do not typically express this enzyme. Additionally, there are a small number of other E. coli strains that do not express b‑D‑glucuronidase.

The choice of tests used in the detection and confirmation of the coliform group of bacteria, including E. coli, can be regarded as part of a continuous sequence. The extent of confirmation with a particular sample depends partly on the nature of the water and partly on the reasons for the examination. The test described in ISO 9308-2:2012 provides a confirmed result with no requirement for further confirmation of positive wells.

Standard first page

Read sample 

Preview this standard in our Online Browsing Platform (OBP)

General information

  • Status
     : Published
    Publication date
     : 2012-07
    Stage
    : International Standard confirmed [90.93]
  • Edition
     : 2
    Number of pages
     : 45
  • Technical Committee :
    ISO/TC 147/SC 4
    ICS :
    07.100.20 
  • RSS updates

Life cycle

Got a question?

Check out our FAQs

Customer care
+41 22 749 08 88

Opening hours:
Monday to Friday - 09:00-12:00, 14:00-17:00 (UTC+1)

  2. Store
  3. Standards catalogue
  4. TC
  5. ISO/TC 147/SC 4
  6. ISO 9308-2:2012