Using the membrane filter procedure, at what temperature should total coliform cultures be incubated?

The correct incubation temperature for total coliform cultures using the membrane filter procedure is 35.5 ± 0.5 degrees Celsius. This temperature is specifically chosen because it closely mimics the optimal growth conditions for coliform bacteria, which typically thrive in warmer environments, such as those found in sanitary conditions.

Incubating at this temperature allows for the most accurate detection of coliforms as it fosters their growth while inhibiting the growth of many other competing microorganisms that may be present in the sample. This is especially important for ensuring that the testing is indicative of fecal contamination, as coliforms are commonly used as indicators of water quality and potential pathogens.

Additionally, the precision of the temperature (35.5 ± 0.5 degrees Celsius) ensures consistency across different tests and laboratories, which is critical for valid comparisons of results. This level of control enhances the reliability of the data generated from the analysis, which is vital for assessing water safety and compliance with health regulations.