In Situ TRAP Assay Detection of Telomerase Activity in Cytological Preparations

In 1994, a highly sensitive assay to detect telomerase activity, called a telomeric repeat amplification protocol (TRAP) assay, was reported by Kim et al. (1 ) with the precise method described in 1995 by Piatyszeck et al (2 ). Many modifications of the original TRAP assay were made later. One example is the use of an internal telomerase assay standard (ITAS) to semiquantify the level of telomerase activity (3 ). Another approach to semiquantify the telomerase activity, using a stretch PCR assay, was reported by Tatematsu et al. With this method, it is possible to detect telomerase activity at the single cell level (4 ). More recently, a commercially available kit has been provided (5 ). Enabling the detection of telomerase activity easily. A body of clinical information has been accumulating and its implications are being obtained (6 ,7 ).