Tyramide amplification technique

Different authors and commercial suppliers have assigned different names to signal amplification using tyramine. For example, tyramine signal amplification (TSA) system and the catalyzed signal amplification (CSA) system are comma-daily available from DuPont NEN Life Science Products, Boston, MA, and DAKO Corporation, Carpinteria, CA, respectively. In addition, the tarns CARD (catalyzed reporter deposition) (Bobrow et al., 1989), TA (tyramide amplification) (Shindler and Roth, 1996), and ImmunoMax (Merz et al., 1995) have been used for the tyramine amplification technique. The use of different names for almost identical procedures has resulted in confusion. To standardize the terminology, the neutral abbreviation, tyramide amplification technique (TAT) should be accepted (Von Wasielewski et al., 1997). 

The tyramide amplification technique is based on the ability of phenolic compounds to become oxidized to highly reactive and unstable intermediates (8). When biotinyl tyramide is oxidized, dimerization with electron-rich aromatic compounds, such as those found in protein molecules, occurs (9). This reaction can be harnessed in immunohistochemistry to generate highly reactive biotinyl-tyramide intermediates that bind rapidly to protein molecules in the immediate vicinity of peroxidase enzymes. This reaction results in the deposition... 

Lebaron, P. Catala, P. Fajon, C. Joux, F. Baudart, J. Bernard, L. A new sensitive, whole-cell hybridization technique for detection of bacteria involving a biotinylated oligonucleotide probe targeting rRNA and tyramide signal amplification. Appl. Environ. Microbiol. 1997, 63, 3274-3278. 

Figure 2. Highly sensitive immunohistochemical detection method. The catalyzed signal amplification system, which employs fluoresceinyl tyramide (FT-CSA), is a representative enhancement technique that is suitable for pathological research with archival tissue sections. The method consists of two steps, an amplification step by first-step peroxidase-labeled antibody and fluoresceinyltyramide (a), and a visualization step by second-step peroxidase-labeled antibody and chromogen (b), in both of which microscopic observation of immunosignals is possible (inset photos HER4 IHC analysis in A431 epidermoid cell lines).

Extensive progress has been attained in determination techniques. Noteworthy is the broad applicability of a homogenic method known as the TRACE method (time-resolved amplified cryptate emission). Another interesting solution, TSA (tyramide signal amplification), employs a technique which amplifies the tyramide signal (Bednarski and Reps, 2003). 

Finally, there are numerous techniques for signal enhancement such as avidin - biotin - complexes and tyramide signal amplification methods. All of these tertiary procedures obviously add to the time parameter of any test, but can add significant staining intensity that is critical in samples with low numbers of antibody binding sites. Determination of methodology for cell staining must be evaluated on the basis of tissue/cells samples to be examined. 

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