PCR-based microsatellite polymorphisms in the detection of loss of heterozygosity in fresh and archival tumour tissue.

PCR-based microsatellite polymorphisms have proved their power in genetic linkage analysis and other identification methods, due to their high information content and even distribution over the chromosomes. In the present study we applied microsatellite polymorphisms to detect loss of heterozygosity in fresh (snap-frozen) and in archival ovarian tumour tissue. Clear allele losses were found in fresh and paraffin embedded tumour samples. Conventional Southern analysis of flanking markers on the same tumour DNA samples confirmed the observed losses detected by microsatellite polymorphisms. Titration experiments suggest that loss of heterozygosity remains detectable in tumour samples despite 60% contamination with normal DNA. This technique provides a fast and reproducible alternative to conventional Southern blotting in the detection of loss of heterozygosity, with the crucial additional advantages of minimal sample requirements, making archival material available for genetic investigation.