There are primarily two types of detection methods used in IHC:
Chromogenic Detection: Uses enzymes such as horseradish peroxidase (HRP) or alkaline phosphatase (AP) conjugated to the secondary antibody. These enzymes catalyze a colorimetric reaction, producing a colored precipitate at the site of antigen-antibody binding. Fluorescent Detection: Uses fluorophore-conjugated antibodies that emit light upon excitation by a specific wavelength. This method allows for multiplexing, where multiple antigens can be detected simultaneously using different fluorophores.
