Developmental validation of a custom-designed Multi-InDel panel: A five-dye multiplex amplification system for...

Area of Science:

• Forensic Genetics
• Molecular Biology
• Human Identification

Background:

• Forensic DNA analysis faces challenges with degraded samples and low DNA quantities.
• Novel genetic markers are crucial for advancing DNA profiling techniques.
• Existing methods like short tandem repeat (STR) kits have limitations in sensitivity and efficiency.

Purpose of the Study:

• To develop and validate a custom Multi-insertion/deletion (Multi-InDel) marker panel for forensic DNA analysis.
• To assess the performance of the Multi-InDel system in terms of sensitivity, inhibitor tolerance, and efficiency with degraded DNA.
• To evaluate the utility of the Multi-InDel system for analyzing mixed DNA samples.

Main Methods:

• Simultaneous amplification of 41 novel Multi-InDel markers and an amelogenin locus.
• Developmental validation study following Scientific Working Group on DNA Analysis Methods guidelines.
• Capillary electrophoresis platform utilized for genotyping.

Main Results:

• Reliable genotyping profiles obtained with as little as 62.5 pg of template DNA.
• Accurate profiles generated despite the presence of PCR inhibitors.
• Superior efficiency compared to STR kits for degraded samples due to amplicon size (<220 bp).
• Effective identification of two-person DNA mixtures with minor contributor DNA as low as 50 pg.

Conclusions:

• The novel Multi-InDel system demonstrates high sensitivity and robustness for forensic DNA analysis.
• The system's efficiency with degraded samples and performance in mixture analysis represent significant advancements.
• This Multi-InDel system shows strong potential as a valuable tool for human identification in forensic science.