Which factors determine the success of an immunohistochemical procedure?

• A. The antigen preservation
• B. The specificity and avidity of the primary antibody
• C. The sensitivity of the detection system
• D. All of the above

Answer: (D)

In immunohistochemistry, success comes from three elements working together: preserving the antigen so it remains recognizable in the tissue, using a primary antibody that is specific for the target and has enough avidity to bind effectively, and applying a detection system that is sensitive enough to reveal that binding without generating excessive background. If the antigen is degraded or masked by improper fixation, even a perfect antibody won’t bind well, leading to weak or absent staining. If the antibody lacks specificity or has low affinity, you’ll get non-specific signals or weak, unreliable staining. If the detection system isn’t sensitive enough, true positive signals can be missed or look faint, making interpretation difficult. Therefore, all of these factors together determine how well an IHC procedure works, which is why the best answer is that all of the above contribute to successful results.