The detection system in immunohistochemistry primarily affects which aspect of staining?

• A. Color of chromogen
• B. Sensitivity and background staining
• C. Tissue fixation
• D. Primary antibody affinity

Answer: (B)

The detection system in immunohistochemistry is what turns antibody binding into a visible signal. It mainly determines how sensitive the assay is and how much non-specific background staining appears, because signal amplification and steps to minimize non-specific interactions depend on the detection reagents (secondary antibodies, polymers, enzymes, or fluorophores). The color seen is produced by the chromogen chosen for the enzyme reaction and is a downstream result of the detection step, while tissue fixation and primary antibody affinity affect antigen preservation and binding rather than signal amplification. So, the detection system best relates to sensitivity and background staining.