Microsatellite instability testing in colorectal cancer using the QiaXcel advanced platform

Microsatellite instability (MSI) is a major predictive and diagnostic marker in several cancers including colorectal carcinomas. Diagnostic testing for microsatellites is generally performed using capillary sequencers, which requires expensive high-end equipment including expensive chemistry using fluorescent dyes labelling the PCR products of interest. In this study we have modified such a diagnostic protocol and established the microsatellite testing on the QiaXcel Advanced platform.

MSI testing was based on a previously established protocol describing a multiplex PCR followed by fluorescent detection of PCR products in a capillary sequencing device. Ten microsatellites were included in the new protocol: BAT25, BAT26, BAT40, D2s123, D10s197, D13s153, D17s250, D18s58, D5s346, and MycI. In this protocol the PCR was demultiplexed and established on the QiaXcel Advanced system (Qiagen, Hilden, Germany).

Making use of a series of FFPE control samples with known MSI status including those with and without MSI a protocol for MSI testing was successfully established on the QiaXcel Advanced platform.

MSI testing for human colorectal cancers using the QiaXcel Advanced system could serve as an economic acceptable tool for rapid diagnostics in laboratories that do not have access to a capillary sequencing unit.