What is the final phase in the MPN procedure?

What is the final phase in the MPN procedure?

• A. Completed
• B. Presumptive
• C. Confirmed
• D. Final Phase

Answer: (A)

In the MPN procedure, testing advances through stages that narrow down the presence of coliforms: a presumptive screen, a confirmatory step, and then a final verification. The last step is the completed test. This phase takes the positive results from earlier stages and performs the final confirmation to ensure the organisms are truly coliforms and to finalize the Most Probable Number. The other terms refer to earlier stages or are not the standard name for the last step, so the correct final phase is completed.

In the MPN procedure, testing advances through stages that narrow down the presence of coliforms: a presumptive screen, a confirmatory step, and then a final verification. The last step is the completed test. This phase takes the positive results from earlier stages and performs the final confirmation to ensure the organisms are truly coliforms and to finalize the Most Probable Number. The other terms refer to earlier stages or are not the standard name for the last step, so the correct final phase is completed.