Question

Why is lab disinfectant often used as a control when testing a new substance's ability to kill microorganisms in broth?

A. It ensures that your testing system is working since you know lab disinfectant will kill certain microorganisms.
B. You are always trying to find something that works better than lab disinfectant.
C. All available answers are correct.
D. Lab disinfectant is very concentrated, so this will allow you to determine how concentrated the test chemical is.

Answer 1

Lab disinfectant is often used as a control when testing a new substance's ability to kill microorganisms in broth to ensure the testing system is working and to compare the effectiveness of the new substance.

Step-by-step explanation:

In testing a new substance's ability to kill microorganisms in broth, lab disinfectant is often used as a control. This is because of several reasons:

1. It ensures that the testing system is working: Since we know that lab disinfectant will kill certain microorganisms, using it as a control allows us to verify that our testing system is functioning properly.
2. Comparison to a known disinfectant: By comparing the effectiveness of the new substance to the lab disinfectant, we can determine if the new substance works better or worse.

Therefore, option A is the correct answer.