Microsatellite Instability (MSI)
MSI – Microsatellite Instability
Formalin-fixed paraffin embedded tissue (FFPE)
This test compares tumor DNA to normal DNA. Therefore, two tissue types must be submitted; slides containing tumor in addition to slides with normal tissue.
Tumor containing block: 5-10 10µm thickness unstained slides with stained H&E of same block.
Normal tissue block: 5-10 10µm thickness unstained slides with stained H&E of same block.
Storage and stability information:
Once per week
Polymerase Chain Reaction (PCR), Capillary Electrophoresis
The Microsatellite Instability assay is used to evaluate tumor tissue to identify patients at high risk for having HNPCC/Lynch syndrome. Tumor tissue is indirectly evaluated for the presence of defective DNA Mismatch repair by analyzing MSI (Microsatellite instability) patterns.