Restriction fragment length polymorphism analysis of ERBB2 oncogene by capillary electrophoresis

Capillary electrophoresis (CE) with a sieving buffer containing ethidium bromide was applied to the detection of PCR-amplified RFLP samples. With CE, in contrast to agarose gel electrophoresis, run times are short, i.e., typically less than 30 min, the capillary can be re-used, and full automation is feasible. The addition of ethidium bromide to the buffer system in conjunction with a field amplification injection technique led to increased sample detectability and resolution. Migration time precision was better than 0.2% RSD with a approximately 12-bp resolution for the DNA fragment sizes of interest. RFLP samples were analyzed for homo- or heterozygosity based on the presence of 500- and/or 520-bp DNA fragments. Special software was used to correct for run-to-run migration time variations, thus facilitating genotype assignment.