[Amplification of immunologic reactions using catalytic deposition at the reaction sites of tyramine derivatives. A decisive gain in sensitivity in immunohistochemistry and in situ hybridization].

In the catalyzed reporter deposition technique, horseradish peroxidase catalyzes the activation of conjugated phenolic compounds resulting in the covalent binding of the radicalized intermediates to electron rich moieties in the protein molecules present at the site of reaction. Comparing the biotinyl-, digoxigeninyl-, and fluoresceinyl-derivatives of tyramine and four immunohistochemical formats, we showed that the most sensitive detection system was that using biotinyl-tyramide and an immunohistochemical technique using a biotinylated secondary antibody followed by a streptavidin peroxidase. Amplification without background staining was obtained in most biotin rich tissues with digoxigeninyl-tyramide. With fluoresceinyl-tyramide, clear signal amplification was observed in the fluorescent microscope. Finally, when compared with standard methods, increased sensitivity was obtained with the fluorescent derivative for detection of hybridized sequences in interphase chromosomes.