Explain Procedure for Performing the Completed Coliform Test?

Completed test is the last step in the Coliform test procedure which is described herewith. Conduct the exercise following the steps enumerated herewith.

1. Label the lactose broth tubes and nutrient agar slants with the source of water sample.

2. Inoculate the lactose broth tubes and nutrient agar slants with the isolated coliform colonies on the EMB/Endo agar plates from each of the experimental water samples.

3. Incubate the inoculated broth tubes and slants at 37°C for 24 hours.

4. Examine lactose broth fermentation tubes for production of acid and gas and nutrient slants for gram reaction and cell morphology.

5. Production of acid and gas in inoculated lactose broth and presence of gram negative rods in nutrient slants indicate a positive complete test and confirms the presence of coliforms in water sample.