E. coli analysis can be performed in a number of ways, including:

 E. coli analysis can be performed in a number of ways, including: 

Membrane filtration

A water sample is filtered through a membrane and placed on culture media that is selective for E. coli. The bacteria grow on the media and form colonies, which are counted and reported as colony forming units (CFUs). 

Biochemical tests

E. coli is a Gram-negative bacterium that ferments lactose and other carbohydrates. For example, E. coli ferments dextrose (D-glucose) by producing mixed acids, which can be made visible with the addition of methyl red indicator. 

 

Solid phase cytometry (SPC)

E. coli in water samples are filtered over a polyester membrane, treated with reagents, and incubated. The induced cells are then labeled, with only the enzymes on the viable cells being labeled. 

PCR

PCR analysis using Afa gene-specific primers can detect E. coli in food samples. 

E. coli analysis can be used to diagnose illnesses caused by E. coli infection. A doctor may send a stool sample to a laboratory to test for the presence of E. coli. The bacteria may be cultured to confirm the diagnosis and identify specific toxins.