Objective: To set up a sensitive and stable technique which has high throughout to detect the instability of microsatellite DNA.
Methods: Genomic DNA extracted from the cancer tissues and their normal tissues were subjected to microsatellite instability(MSI) analysis on five of DNA markers in 115 sporadic colorectal cancers by means of PCR and ion-pair reversed-phase high performance liquid chromatography. Genomic DNA extracted from lymphocytes in blood of 20 normal persons were analysed and used as the standard control.
Results: Seventeen (14.8%) MSI-H and 23(20.0%) MSI-L were found in 115 sporadic colorectal cancers. The rates of MSI in the young patients and old patients were much higher than that in the middle-age patients (P<0.05). And the rate of MSI in low differentiation group was also much higher than that in high or middle differentiation groups (P<0.05).
Conclusion: The method the authors developed is a sensitive and accurate technique to detect MSI and has a high throughput.