Analysis of microsatellite instability in colorectal carcinoma by microfluidic-based chip electrophoresis

Microsatellite analysis is an important tool in clinical research and molecular diagnostics because microsatellite instability (MSI) occurs frequently in various types of cancer. Approximately 10-15% of colorectal, gastric and endometrial carcinomas are associated with MSI, and this has an impact on clinical prognosis. The microsatellite loci Bat25, Bat26, D2S123, D5S346 and D17S250, recommended by the Bethesda guidelines, were analysed by microfluidic-based on-chip electrophoresis in 40 cases of colon carcinoma with known MSI status. In all cases, microfluidic separation of the PCR amplicons resulted in highly resolved, distinct patterns of each of the five microsatellite loci. Detection of MSI could be demonstrated by microsatellite-loci-associated, well-defined deviations in the electropherogram profiles of tumour and non-tumour material, and confirmed the classification of MSI cases performed by conventional technology. In conclusion, microfluidic chip technology is a simple and reliable approach for MSI detection that allows label-free and very fast analysis of microsatellite amplicons.