Multiplex immunohistochemical (mIHC), also known as Tyramide dignal amplification (TSA), is a class of enzymatic assays that utilize Horseradish Peroxidase (HRP) for high-density in situ labeling of target proteins or nucleic acids. Horseradish Peroxidase (HRP) is a class of enzymatic assays that use Horseradish Peroxidase (HRP) for high-density in situ labeling of target proteins or nucleic acids. The method is based on multiple cis-immunostaining with tyramine signal amplification, allowing for the simultaneous detection of multiple targets on a single cell or tissue sample for a comprehensive study of cellular composition, cellular function and cellular interactions.

Various sample types are available, including hard-to-obtain free cell samples, precious FFPE samples, or frozen tissue sections.