In order for the Primary Antibody to be a good selection, it must provide which combination?

• A. High sensitivity and high specificity.
• B. High affinity with low specificity.
• C. Low sensitivity with high specificity.
• D. Moderate sensitivity and specificity.

Answer: (A)

In selecting a primary antibody for immunohistochemistry, the goal is to detect the target antigen reliably and accurately. High sensitivity means the antibody can reveal the antigen even when it’s present at low levels, ensuring true positives aren’t missed. High specificity means the antibody binds mainly to the intended antigen with little cross-reactivity to other proteins, which minimizes background staining and false positives. Together, these two qualities give a clear, trustworthy signal that truly reflects the presence of the target. If specificity is low, you’ll get a lot of misleading staining from other proteins; if sensitivity is low, you’ll miss genuine signal. Moderate levels won’t maximize detection or accuracy. Hence, high sensitivity and high specificity is the best combination.