Quantitative Detection of Telomerase Components by Real-Time, Online RT-PCR Analysis with the LightCycler

Telomeres are specialized DNA/protein structures, located at the ends of eukaryotic chromosomes, that consist of small, tandemly repeated DNA sequences. They have an essential role in the stable maintenance of the eukaryotic chromosome by preventing nucleolytic degradation, end-to-end fusion, irregular recombination, and other events that are normally lethal to a cell (1 ). In most normal tissues telomeres progressively shorten with each replication cycle as a result of the end-replication problem (2 ). Because germline cells, stem cells, and especially tumor cells exhibit a prolonged or even infinite life span, it was proposed that these cells must possess a particular mechanism for maintaining telomere length (3 ).