A Novel Multiplex Assay for an Ancestry-Informative Marker (AIM) Panel of INDELs

The current standard for forensic laboratories in criminal casework is to use Short Tandem Repeat (STR) markers to develop an evidentiary profile to compare with a reference profile. Commercially available STR amplification kits yield amplicons 100 to 500 base pairs (bp) in length. A common problem encountered by scientists is degraded DNA samples that are only 180-200 bps in length. These samples fail to amplify some loci and therefore produce an incomplete STR profile. STRs are used for identity testing because of their high discrimination power. However, there are cases where no STR match was obtained through a DNA database search and thus no investigative lead is obtained. The bioancestry of the donor of the sample could aid law enforcement in such cases. Another class of markers that could provide investigative value from degraded DNA samples is Ancestry-Informative Marker (AIM) Insertion/Deletions (INDELs). INDELs are polymorphisms that can be amplified from degraded samples due to their smaller amplicon size. AIMs have the ability provide bioancestry information. This project used a previously developed panel of AIM-INDEL markers to develop a multiplex PCR-based assay specifically for these identity-testing applications.