PCR-free electrochemical assay of telomerase activity

In this paper, we report a non-PCR-based electrochemical assay that can detect telomerase activity. Telomerase from HeLa cells may induce telomerization of thiolated primers immobilized on a gold electrode surface. With the telomerization reaction, more and more guanine-rich telomeric repeats are formed, so the electrochemical oxidation signal of guanine at about 1.00 V, which is utilized to indicate the elongated guanine-rich telomeric repeats tethered to the primers, will be increased. This assay method can detect the telomerase activity originated from 3000 HeLa cells and thus holds promise as a simple and sensitive approach in clinical diagnosis of cancer. (c) 2008 Elsevier B.V. All rights reserved.