Standard TRAP Assay

Abstract

The polymerase chain reaction (PCR) based telomeric repeat amplification protocol (TRAP) assay, to detect telomerase activity was originated by Kim et al. in late 1994 (1) and revolutionized the field of telomere/telomerase research in aging, but particularly in cancer. Thus, the TRAP assay has provided the stimulus for the current interest in the detection of telomerase activity in a wide variety of human malignancies with regard to its potential clinical utility, as a diagnostic adjunct in the early diagnosis of malignancy, as a potential prognostic indicator (2-7) or as a means to identify telomerase inhibitors (7, 8). Previously, investigators had to rely on the elaborate conventional primer extension assay for detecting telomerase activity, which requires large amounts of telomerasepositive cells (2×10⁸), thus limiting the number of primary human specimens that could be examined easily (9,10). A major problem with the conventional assay is also the weak signal strength, necessitating extensive autoradiographic exposure times (more than a week). Moreover, enhancement of signal would require enrichment of the telomerase fraction and additional time consumption (11).