AAT Bioquest

What is Tyramide Signal Amplification (TSA)?

Posted March 10, 2020


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Tyramide signal amplification (TSA) is a novel technique designed to enhance the detection of low-abundance targets (e.g. proteins and nucleic acid sequences). It can be readily integrated into any application that utilizes horseradish peroxidase (HRP) in its protocol. These applications include ELISA, immunocytochemistry (ICC), immunohistochemistry (IHC) and in situ hybridization (FISH). Advantages of tyramide signal amplification, include:

  • Detection of low-abundance targets
  • Higher precision and sensitivity up to 100-fold that of conventional ICC, IHC and FISH methods
  • Easy integration with ICC, IHC and FISH applications
  • Conservation of primary and secondary antibodies

TSA Principle & Workflow

TSA - sometimes called Catalyzed Reporter Deposition or CARD, is an enyzme-mediated detection method that utilizes the catalytic activity of HRP for the covalent deposition of labeled tyramide on and near target proteins or nucleic acid sequences in situ. In the presence of hydrogen peroxide (H2O2), HRP converts labeled tyramide substrates into highly-reactive, short-lived tyramide radicals that rapidly bind to tyrosine residues on and proximal to the enzyme site. These labels can be detected by standard chromogenic or fluorescent techniques.

TSA labeling procedure consists of the following steps:

  1. Sample preparation – fixation and permeabilization of cells or tissue sample
  2. Blocking of nonspecific epitopes
  3. Binding with primary antibody, biotinylated primary antibody or biotinylated nucleic acid probe
  4. Binding with HRP-secondary antibody or HRP-streptavidin
  5. Incubation with tyramide substrate
  6. Mount sample and image signal


TSA workflow illustration
Figure 1. Workflow for tyramide signal amplification (TSA). With workflow similar to conventional ICC and IHC methods, TSA can achieve sensitive detection of desired targets in a few simple steps.

Available tyramide reagents

Product NameEx/Em (nm)εΦSizeCat#
Azido-Cy5 tyramide650/669250,0000.271 mg11061
Cy3 tyramide554/568150,0000.041 mg11065
Cy5 tyramide650/669250,0000.271 mg11066
AF488 tyramide reagent499/52073,0000.92200 slides11070
AF546 tyramide reagent561/572112,0000.1200 slides11075
AF594 tyramide reagent590/61892,0000.66200 slides11082
iFluor® 488 tyramide491/51675,0000.9200 slides45100
iFluor® 555 Tyramide556/569100,0000.64200 Slides45105
iFluor® 647 Tyramide654/669250,0000.25200 Slides45110
Additional resources

iFluor™ 488 tyramide Product Page

Power Styramide™ Signal Amplification (PSA™)