Measurement of Telomere Length: A New Assay Using QuantiGene Chemistry on a Luminex Platform

Background: Telomeres are tandem repeats of sequences present at the end of the chromosomes that maintain chromosomal integrity. After repeated cell division, telomeres shorten to a critical level, triggering replicative senescence or apoptosis, which is a key determinant of cellular aging. Short telomeres also contribute to genome instability and are a hallmark of many cancers. There are several methods for estimating telomere length (TL) from extracted DNA samples. Southern blot is accurate but requires a large quantity of DNA and is expensive. qPCR is cost-effective and requires a small quantity of DNA and is therefore widely used for large-scale epidemiologic studies; however, it typically requires triplicates. We describe a novel multiplexed probe-based non-PCR method for TL measurement. Methods:Asmall amount ofDNA (50ng) is hybridized to telomere repeat sequence–specific probes (T) and a reference single gene probes (R). T and R signals are detected from a single reaction well containing the same inputDNA. BranchingDNA technology is used to amplify the signal,which is detected byLuminex technology. Results:The intra- and interassayCV (3%and5%, respectively) shows theprecision of the newassay and themeasurements from singlewell correlatedwellwith traditional single-plex qPCR run in triplicate (r 0.7 to 0.8). The assay was also validated in an independent set of samples using Southern blot (r 0.74). Conclusion: We describe a novel assay for TL assessment using the Luminex platform. Impact: This may offer an alternative cost-efficient way to study TL in extracted DNA samples