iFluor® 633 tyramide

For many immunohistochemical (IHC) applications, traditional enzymatic amplification procedures are sufficient for achieving adequate antigen detection. However, several factors limit their sensitivity and utility. Tyramide signal amplification (TSA) has proven to be a particularly versatile and powerful enzyme amplification technique with improved assay sensitivity. TSA is based on the ability of HRP, in the presence of low concentrations of hydrogen peroxide, to convert labeled tyramine-containing substrate into an oxidized, highly reactive free radical that can covalently bind to tyrosine residues at or near the HRP. To achieve maximal IHC detection, tyramine is prelabeled with a fluorophore. The signal amplification conferred by the turnover of multiple tyramide substrates per peroxidase label results in the ability to detect low-abundance targets with ultrasensitive precision and reduces the amount of antibodies and hybridization probes needed. In IHC applications, this method can also enhance sensitivity in cases where the primary antibody dilution needs to be increased to reduce nonspecific background signals or overcome weak immunolabeling due to suboptimal fixation procedures or low levels of target expression. The iFluor® 633 tyramide contains the bright iFluor® 633 that can be readily detected with the standard Cy5 filter set. iFluor® dyes have higher fluorescence intensity, increased photostability, and enhanced water solubility, resulting in fluorescence signals with significantly higher precision and sensitivity. iFluor® 633 tyramide is an ideal probe for applications where the common tyramides may face interference due to the inherent fluorescence of tissues or other samples.