A novel magnetic bead-based assay with high sensitivity and selectivity for analysis of telomerase in exfoliated cells from patients with bladder and colon cancer

Abstract

Telomerase activity is elevated in more than 85% of cancer cells and absent in most of the normal cells and thus represents a potential cancer biomarker. We report its measurement in colon and bladder cancer cells captured using antibody-coated magnetic beads. The cells are lysed and telomerase activity is detected using a biosensor assay that employs an oligo-nucleotide containing the telomerase recognition sequence also covalently coupled to magnetic beads. Telomerase activity is measured by the incorporation of multiple biotinyated nucleotides at the 3′-end of the oligonucleotide strands during elongation which are then reacted with streptavidin-conjugated horseradish peroxidase. A lumine..