iFluor(R) 680 Tyramide *Superior Replacement for Opal 690*

Correction Factor (260 nm): 0.097. Correction Factor (280 nm): 0.094. Extinction coefficient (cm^-1 M^-1): 220000 (aqueous buffer (pH 7.2)). Excitation (nm): 684. Emission (nm): 701. Quantum yield: 0.23 (aqueous buffer (pH 7.2)). Traditional enzymatic amplification procedures are sufficient for many immunohistochemical (IHC) applications for achieving adequate antigen detection. However, several factors limit their sensitivity and utility. Tyramide signal amplification (TSA) has proven to be a remarkably 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(R) 680 tyramide contains the bright iFluor(R) 680, detectable with the Cy5.5 filter set. iFluor(R) dyes exhibit higher fluorescence intensity, increased photostability, and enhanced water solubility, resulting in fluorescence signals with significantly higher precision and sensitivity. iFluor(R) 680 tyramide is an ideal probe for applications where common tyramides might encounter interference from the intrinsic fluorescence of tissues or other samples. iFluor(R) 680 is a superior alternative to Alexa Fluor(R) 680, Opal 690, or other spectrally comparable tyramide conjugates.