Laboratory temperature variation is a previously unrecognized source of genotyping error during capillary electrophoresis

Capillary electrophoresis is being used increasingly for microsatellite genotyping. Here, we report that laboratory temperature greatly affects the estimated allele size, with 5 degreesC changing the estimated allele size by up to 0.7 bp. With accurate room temperature control, this variation would be relatively unimportant but unfortunately, a questionnaire shows that daily and seasonal laboratory temperature differences are often substantial. One solution is to use a set of reference genotypes, which also greatly assists comparisons between different platforms.