Microsatellite Instability (MSI) PCR

​The Microsatellite Instability (MSI) PCR assay is intended to be used as a screening test for Lynch Syndrome (hereditary nonpolyposis colorectal cancer syndrome).

This test will be a reflex test on resection specimens from ALL individuals with new histologically diagnosed colorectal cancer (CRC) from SGH and NCC (including NCC at CGH).

​Paraffin embedded tissue blocks sent to the Histopathology Section.

Alternatively, unstained slides can be sent to the Histopathology Section. At least 8 sections of 8 µm thickness (or 12 sections of 5 µm thickness for smaller samples) each of both tumour and normal tissue, should be sent together with one H&E slide, 4 µm thick with a coverslip as a reference slide. Tumour content must be indicated and preferably at least 50% (samples with less than 30% tumour will be rejected).

​In-house developed Multiplexed Polymerase Chain Reaction (PCR) with fragment length analyses for 5 quasi-monomorphic mononucleotide repeats (BAT25, BAT26, NR21, NR24 and NR27)

​Microsatellite stable, Microsatellite Unstable, Inconclusive

2-8 days

Thursdays