Fluorescent detection is a technique used in immunohistochemistry to visualize multiple antigens simultaneously. It is based on the use of fluorophores that emit light when excited by a light source. The fluorophore is conjugated to the primary antibody for direct detection and to the secondary antibody for indirect detection. 

• Fluorescent dyes offer a narrower emission spectra and a wider variety of colors compared to chromogenic dyes, which makes multiplexing easier. 
• Researchers can identify co-localized targets separately using fluorescent dyes for enhanced target co-localization. 
• Fluorescent dyes make it easier to visualize both, rare and highly abundant targets, on the same slide thanks to a higher dynamic range. 
• The substrate addition step is eliminated in fluorescent detection, resulting in fewer procedural steps.