Which of the following describes the three phases of testing in the MPN test?

In the context of the Most Probable Number (MPN) test, the phases of testing are essential for detecting and estimating the concentration of coliform bacteria in water samples. The correct terminology used is "Presumptive," "Confirmed," and "Completed," which aligns perfectly with standard microbiological testing protocols.

The Presumptive phase involves the initial inoculation of the sample into selective media, where growth indicates a possible presence of coliforms. This step helps to narrow down which samples may contain the organisms of interest.

In the Confirmed phase, confirmatory tests are conducted to validate the results from the presumptive phase. This often involves examining growth characteristics or biochemical tests on colonies isolated from the presumptive broths to definitively identify coliform bacteria.

The Completed phase is the final step where additional tests confirm the presence of coliform organisms and assess their characteristics. This phase ensures the reliability of the test results, following up on the previous phases to provide a thorough validation.

Using the correct terminology is crucial in accurately communicating and understanding the testing process, as the MPN test is a widely recognized method for assessing water quality.