Label-free detection of telomerase activity using guanine electrochemical oxidation signal

Date

2007-11-15

Author

Eskiocak, Ugur
Ozkan-Ariksoysal, Dilsat
Ozsoz, Mehmet
Öktem, Hüseyin Avni

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Telomerase is an important biomarker for cancer cells and its activation in 85% of all cancer types confers a clinical diagnostic value. A label-free electrochemical assay based on guanine oxidation signal to measure telomerase activity is described. This developed technology combined with a disposable sensor, carbon graphite electrode (CGE), and differential pulse voltammetry (DPV) was performed by using PCR amplicons with/without telomeric repeats as the guanine oxidation signal observed at +1.0 V measured after the immobilization of PCR products. Guanine oxidation signal was chosen as a measure of telomerase activity because a substantial increase in the number of guanines was introduced by the action of telomerase which adds hexameric repeats (TTAGGG)(n) that contain 50% guanine. The developed assay was shown to specifically measure telomerase activity from cell extracts, and elongation rates increased linearly in a concentration dependent manner. Telomerase activity could be detected in cell extracts containing as low as 100 ng/mu L of protein. All of the electrochemical measurements were also confirmed with the conventional TRAP-silver staining assay. Rapidity, simplicity, and the label-free nature of the developed assay make it suitable for practical use in quantitative determination of telomerase activity from clinical samples for diagnosis of cancer.

Subject Keywords

Analytical Chemistry

URI

https://hdl.handle.net/11511/45989

Journal

ANALYTICAL CHEMISTRY

DOI

https://doi.org/10.1021/ac071014r

Collections

Department of Biology, Article

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Citation Formats

U. Eskiocak, D. Ozkan-Ariksoysal, M. Ozsoz, and H. A. Öktem, “Label-free detection of telomerase activity using guanine electrochemical oxidation signal,” ANALYTICAL CHEMISTRY, pp. 8807–8811, 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/45989.