Which of the following is a polymer-based detection method used in IHC?

• A. HRP based Method
• B. AP based Method
• C. ABC method
• D. Polymer based detection methods

Answer: (D)

Signal amplification in IHC is achieved by detection systems that increase the reporting signal at the antigen site. Polymer-based detection uses a polymer backbone bearing multiple enzyme molecules attached to secondary antibodies, so one binding event yields many enzyme labels and a stronger chromogenic signal. This approach enhances sensitivity and can reduce background compared with biotin–avidin systems. The HRP- and AP-based methods rely on a single enzyme per antibody conjugate, while ABC uses an avidin–biotin complex; neither uses a polymer scaffold, so they are not polymer-based.