Telomeric repeat amplification protocol assay

The TRAP (telomeric repeat amplification protocol) assay is a widely used method for detection of telomerase activity. This technique measures the telomerase activity present in cell extracts. Briefly, cellular extract containing telomerase activity is incubated with a telomeric substrate (a short strand of DNA onto which the telomerase wiU. attach the telomeric repeats) followed by polymerase chain reaction (PCR) amplification of the elongated telomere. Detection of the PCR product is by a number of methods, including gel electrophoresis, radiometric detection, ELISA, and real-time PCR detection. ... 

Telomerase activity is typically measured using the Telomeric Repeat Amplification Protocol (TRAP) assay. In the TRAP assay, products of the telomerase reaction are quantified following their PCR amplification [20, 21], The assay is exquisitely sensitive and incorporates an internal standard (ITAS) with which to normalize signals for differences in PCR efficiency. Telomerase activity is calculated as the ratio of the intensity of the telomeric products to that of the ITAS. With this assay, telomerase activity can be measured in a wide range of specimens, from tissue biopsies to cell pellets [22]. High throughput assays have been developed to adapt the telomerase assay to the clinical environment. Many of these new assays take advantage of fluorophores that alleviate the use of radioisotopes and facilitate the quantification of PCR products. 

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