Microsatellite instability (MSI) is a genomic alteration in the length of microsatellites provoked by a deficient DNA mismatch repair system. MSI is known to occur in several types of cancer e.g., colorectal cancer (CRC), which accounts for 10.7% of newly diagnosed cancers globally (3’rd most occurring) according to World Cancer Research Fund’s data (2020).
Identification of MSI in tumours is important as a predictive factor of response to different therapies, in particular to immune checkpoint inhibitors, and accordingly the need for MSI analysis of these patients has significantly increased. The MicroSight® MSI 1-step HRM Analysis assay analyses five well-described mononucleotide microsatellite sequences: BAT25, BAT26, NR22, NR24, and MONO27, by Real-Time PCR and HRM. The assay evaluates microsatellite length of patient tumour DNA to patient non-tumour DNA or a universal reference, which makes it a valuable stratification tool for assisting cancer treatment planning. After the Real-Time PCR and HRM, a semi-automatic analysis will be made by the instrument software giving objective results in less than 2 hours.
MicroSight® MSI 1-step HRM Analysis assists in making the proper treatment plan for cancer patients. It provides results in less than two hours, has flexibility through two versions, gives precise analysis of up to seven patients simultaneously, and does so all in one instrument.
Paired Samples: MicroSight® MSI 1-Step HRM Analysis assay offers an adaptive analysis of either paired or unpaired samples. Purified patient tumor and non-tumor DNA is added to individual 5-well PCR strip in the paired samples analysis. The strips are analysed in a BaseTyper™ 48.4 Real-Time PCR Instrument, where each run allows for quick analysis of up to 4 different patients simultaneously (4 sets of 2×5-well strips).
The unique analysis of each patient’s specific DNA constitution Needs only 2 positive microsatellite loci for identification A quick, simultaneous 4-patient analysis.
Unpaired Samples: The unpaired sample analysis by MicroSight® MSI 1-Step HRM Analysis assay only needs tumour DNA from the patient, which is then compared to a Universal Reference DNA included in the kit. This allows for analysis of up to seven different patients simultaneously per Real-Time PCR run (7x patient 5-well strips + 1 Universal Reference 5-well strip).
High throughput by use of Universal Reference DNA Needs 3 positive microsatellite loci A quick, simultaneous 7-patient analysis No requirement for matched uninvolved biopsy.
Advantages of MicroSight® MSI:
Results in less than two hours Minimal hands-on time Objective analysis – No biased data interpretation One instrument analysis – Low risk of cross contamination