To specific target sequence of telomerase product, a fluorogenic duplex scorpion primer has been designed. A probe element attached at the 5'-end of it can specifically detect target gene. A PCR blocker—carbon chain with C₃ group, whose length is as the same as a base pair, is joined between the primer sequence and the probe in the duplex scorpion primer. A fluorescence signal is only produced when the probe sequence is hybridized with the target gene in the extended duplex scorpion primer. Using this technology, a novel method has been developed for quantitative assay of telomerase product by real-time PCR. Accurate quantitative assay can be achieved with sample detected within 0.15～1.50×10³ amol/μL under fast cycling conditions. The linear correlation factor R²=0.9992. The method is specific, simple and without post-PCR manipulation.

Key words: duplex scorpion primer, telomerase, real-time assay, polymerase chain reaction(PCR)