Microsatellites are regions of DNA repeats with different lengths, i.e., instability, highlighting DNA mismatch repair gene deficiencies. Typical repeat units are between 1-6 base pairs and the number of repeats vary from person to person such that each person has a set length of these microsatellites in their genome. Measurements of MSI have traditionally been performed using qPCR/CE fragment length analysis methods, or immunohistochemistry (IHC), but new methodologies such as digital droplet PCR (ddPCR) and Next Generation Sequencing (NGS) are now being applied to determination of MSI status of cancer patients. High incidence of microsatellite instability (MSI) has been linked to favorable outcomes in immuno-oncology (I-O) treatment response by patients with diseases such as Lynch Syndrome and colorectal cancer. Hence determination of MSI status for cancer patients is important in I-O therapeutics management.
LGC SeraCare has developed microsatellite instability (MSI) reference materials that support qPCR and NGS assays that target a range of short tandem repeat regions commonly analyzed for microsatellite instabilities. For assays that target specific mono and dinucleotide repeats such as BAT-25, BAT-26, NR-21, NR-24, MONO-27, we have created MSI reference materials containing these markers blended at two different allele frequency (AF) levels – 5% and 20%. Additionally, for NGS MSI assays that analyze for a large number of microsatellite loci across the human genome, we have a human diseased cell line-based MSI-High reference material for such analysis. These products are quantitated by PCR (qPCR/CE and ddPCR) and by targeted NGS assays to support all product claims.
FEATURES AND BENEFITS • Cell line or plasmid-based MSI reference material mix for analysis in molecular assays or NGS • Offered as tumor-only (MSI-High) or tumor-normal (AF5% and AF20%) options • Support MSI assay validation, LoD determination, and routine detection of MSI markers in cancer patient samples • Variant AFs (AF5% and AF20% products) quantitated by ddPCR and qPCR/CE fragment length analysis assays • Normal background DNA is a highly characterized GM24385 human genomic DNA known to be microsatellite stable (MSS) • Manufactured within cGMP compliant and ISO 13485 certified facilities