Multiplex detection of microsatellite variation by capillary gel electrophoresis

The 13 microsatellite loci in the CODIS set include thee subsets that vary over distinct ranges of base pairs, such that it is possible to combine multiple microsatellites for analysis in a single multiplex electrophoresis experiment. In the example, four of the markers show allelic variation occuring in four non-overlapping ranges between 90 ~ 360 bp. Note that at each locus, the individual tested shows two prominent peaks corresponding to two alleles (heterozygous), as expected for highly polymorphic marker. In other cases, an individual may be homozygous for a single allele, in which case only a single peak would be seen.

Figure ©2012 TA Brown, Introduction to Genetics (1st ed.); additional text ©2013 by Steven M. Carr