For ultimate detection sensitivity, tyramide-based amplification techniques are widely used in fluorescent immunodetection and FISH procedures to visualize targets with low expression levels or suboptimal fixation. Tyramide signal amplification (TSA) is an enzyme-mediated detection method that uses horseradish peroxidase (HRP) to generate high-density labeling of a target protein or nucleic acid in situ. This technology can be used with high-performance Alexa Fluor® dyes, conventional fluorescent dyes, or colorimetric detection systems.