PCR-BASED MICROSATELLITE POLYMORPHISMS IN THE DETECTION OF LOSS OF HETEROZYGOSITY IN FRESH AND ARCHIVAL TUMOR-TISSUE

PCR based microsatellite polymorphisms have proved their power in gene tic linkage analysis and other identification methods, due to their hi gh information content and even distribution over the chromosomes. In the present study we applied microsatellite polymorphisms to detect lo ss of heterozygosity in fresh (snap-frozen) and in archival ovarian tu mour tissue. Clear allele losses were found in fresh and paraffin embe dded tumour samples. Conventional Southern analysis of flanking marker s on the same tumour DNA samples confirmed the observed losses detecte d 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 re producible alternative to conventional Southern blotting in the detect ion of loss of heterozygosity, with the crucial additional advantages of minimal sample requirements, making archival material available for genetic investigation.