In testing, which group is expected to produce a positive result?

• A. Positive control
• B. Negative control
• C. Experimental group
• D. Test sample

Answer: (A)

The main idea is that a positive control is used to confirm the assay can detect a signal when the target is present. It contains a known positive material so you expect a positive outcome, which validates that the reagents, instruments, and protocol are working as intended. This helps you trust results from the experimental group, because if the positive control shows a positive result, you know the test can reveal the target when it’s there. A negative control should produce no signal and helps reveal contamination or background noise. The experimental group is where you apply the variable you’re testing, and its outcome shows whether that variable has the intended effect. A test sample is any specimen under study and does not by itself guarantee a positive result.