Minisatellites are tandem repeat arrays of middle size (5-100 bp) repeat units widely distributed in eukaryotic genomes. They have been related to several important features of human genome biology, including gene regulation, chromosomal fragile sites, and imprinting. In this report, we have critically assessed and employed heteroduplex analysis (HA) for the identification of different human minisatellite MsH43 alleles. This minisatellite is organized as a repeat array of 5-6 bp units spanning 0.5 kbp. Our results demonstrate that this procedure is an easy, rapid, and reliable method to document allelic diversity for this locus. This work suggests that HA will also be a useful tool for studying the polymorphism of other minisatellites with small repeat units.