Colititer

Determination of the coliter in culture tubes with a lactose-peptone broth and with inserted Durham tubes. The last (right) culture tube is not overgrown

The colititer is the amount of water (usually in milliliters ) determined by the titer method , in which an Escherichia coli bacterium can just be detected. A culture medium that is selective for Escherichia coli is used for the titer method and a culture batch is assessed as positive if gas is formed in it by the metabolism from lactose , which is contained in small glass tubes (called Durham tubes) which are closed on one side and inserted into the culture vessels with the opening facing downwards. is caught.

The Colititer is a benchmark for assessing the contamination of drinking water and wastewater .