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. Commercially available STR amplification kits yield amplicons 100 to 500 base pairs (bp) in length. Commonly, forensic DNA samples are highly degraded to approximately 180-200 bps in length, resulting in incomplete STR profiles. Therefore, markers that can be generated with smaller amplicons may be better suited for degraded DNA samples. Additionally, there are cases where no STR match was obtained through a DNA database search and thus no investigative lead is obtained. The bioancestry of a sample donor could aid law enforcement in such cases. A 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 tested the hypothesis that a multiplex PCR-based assay of INDELs can be developed, and subsequently be analyzed by capillary electrophoresis for population identity testing applications. The use of this assay would require no additional tools or machinery than what already is in standard forensic laboratories. To test this hypothesis, a previously developed panel of AIM-INDEL markers was used to develop this multiplex assay.