Genetic research to evaluate plus stutter on D18S51 locus

The PCR amplification of STR loci typically produces a minor byproduct called minus stutter (or plus stutter) that is one repeat unit shorter (or one repeat unit longer) than the original product. These stutters cause some problems that affect the result of STR typing and complicate when comparing results of STR typing. It is necessary to remove the stutter in the forensic STR typing. Minus stutter is filtered out automatically by setting of the analysis software. On the other hand, plus stutter at most loci in STR Kits does not have such setting and it is in particular difficult to distinguish between the original peak and stutter peak.