The MSI Analysis System, Version 1.2, is a fluorescent multiplex PCR-based method detect microsatellite instability (MSI), a form of genomic instability. This instability is due to insertion or deletion of repeating units during DNA replication and failure of the mismatch repair system (MMR) to correct these errors. MSI analysis typically involves comparing allelic profiles of microsatellite markers generated by amplification from matching pairs of test samples, which may be MMR-deficient, and normal tissue samples. New alleles in the abnormal sample not found in the corresponding normal sample indicate the presence of MSI. MSI analysis can be used as a screening method to identify samples for further characterization.
The MSI Analysis System, Version 1.2, includes fluorescently labeled primers for co-amplification of seven markers for analysis of the MSI-high (MSI-H) phenotype, including five nearly monomorphic mononucleotide repeat markers (BAT-25, BAT-26, MONO-27, NR-21 and NR-24) and two highly polymorphic pentanucleotide repeat markers (Penta C and Penta D). Amplified fragments are detected using ABI 3130 or 3500 series Genetic Analyzers (as well as other legacy instruments) after spectral calibration.