MSI-H can be detected using a variety of methods, including polymerase chain reaction (PCR)-based assays and next-generation sequencing (NGS). These techniques compare the length of microsatellite sequences in tumor tissue to those in normal tissue. A significant difference in length indicates the presence of MSI-H. Immunohistochemistry (IHC) can also be used to detect the loss of MMR proteins, which is indicative of MSI-H.
