Video

Most Probable Number Demo

The most probable number (MPN) test method estimates the number of indicator bacteria that is most likely present in a water sample. This demo will show how to conduct a MPN test using a Hach Pathoscreen Test Kit.

Multiple samples (1-10 mL) of the same water to be tested are added to a culture media in sterile tubes and incubated at a particular temperature for a fixed time (usually 24 hours). By counting the number of tubes showing a positive result and comparing with a standard table, a statistical estimate of the most probable number of bacteria can be made. The results are reported as MPN per 100 mL.

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CAWST is a Canadian charity and licensed engineering firm. We address the global need for safe drinking water and sanitation by building local knowledge and skills on household solutions people can implement themselves.