High-resolution detection of loss of heterozygosity of dinucleotide microsatellite markers

Dinucleotide microsatellite markers are frequently investigated to study in heritance, genetic stability, and allele frequency distribution in a wide v ariety of genetic disorders. Previous studies have encountered significant problems regarding resolution and detection of dinucleotide microsatellites . In this study, a useful method to investigate loss of heterozygosity (LOH ) of dinucleotide microsatellite markers is described that involves the use of nondenaturing (Spreadex(R)) submerged gel electrophoresis and SYBR(R) G reen I nucleic acid staining. This method omits the gel casting step and th e use of hazardous radioactive materials frequently used in many microsatel lite studies that employ polyacrylamide gel nucleic acid denaturation analy sis. Using this method, 62 patients' paired tumor and normal samples were i nvestigated to detect allele deletions in a region of chromosome 7q31.1, wh ich is believed to harbor a tumor suppressor gene. Interpretable results we re obtained in all cases. These results were compared to those attained usi ng ABI Prism(TM) Genetic Analyzer 310 and Gene-Scan(R). There were no discr epancies in results obtained between the two assays. The Spreadex system is cheap, does not require larger equipment costs, and may prove to be a usef ul system for high-throughput investigation of microsatellites. It may have diagnostic significance and also prove useful if applied to population-bas ed genomic screening and linkage analysis.