Detection of telomerase activity in human cells with telomeric repeat amplification protocol by silver staining

Telomerase is a ribonucleoprotein enzyme, which synthesizes telomeric repeats （TTAGGG） n.While germline cells and most malignant tumor cells express telomerase activity, normal somatic cells aregenerally deficient in telomerase activity. Our objective was to detect telomerase activity of human cells bysilver staining with telorneric repeat amplification protocol （TRAP） which is easy and quick. Comparing withradioisotopic TRAP, we examined the telomerase activity in telomerase-positive 293-cell and RNase-pretreated and heat-pretreated negative controls by silver staining TRAP. We detected telomerase activity in 2 strainsof human liver tumor cells （QGY7701 and SMMC7721 ）. The 293 cells （only 10 cells） and the 2 strains ofhuman liver tumor cells were all positive. while telomerase activity was not detected in the negative controls.These data suggest that non-radioisotopic silver staining TRAP is a specific, sensitive and fast assay fortelomerase activity. It was verified that the 2 strains of human liver tumor cells express telomerase activity.