Extensive evaluation of DNA polymerase performance for highly degraded human DNA samples

Area of Science:

• Forensic Science
• Molecular Biology
• Genetics

Background:

• Degraded human DNA is a significant challenge in forensic studies, often leading to failed DNA analysis.
• Previous evaluations of DNA polymerase performance for amplifying degraded DNA are limited.
• Optimizing polymerase selection is crucial for successful amplification from challenging samples.

Purpose of the Study:

• To evaluate and compare the performance of nine commercially available DNA polymerases for the successful amplification of highly degraded human DNA.
• To identify the most efficient DNA polymerases for ancient DNA (aDNA) samples using real-time PCR and gel electrophoresis.

Main Methods:

• Tested nine DNA polymerases, including those known for handling PCR-inhibitory samples, on 200 ancient DNA samples.
• Utilized real-time PCR and agarose gel electrophoresis for analyzing single-copy gene amplification.
• Conducted screening tests and further evaluations to assess amplification success rates and reproducibility.

Main Results:

• Pico Maxx HF, FastStart Taq, and Ex Taq HS showed higher success rates than the control (AmpliTaq Gold).
• Ex Taq HS (65/180), FastStart Taq (64/180), and Pico Maxx HF (62/180) outperformed AmpliTaq Gold (52/180).
• Combining Ex Taq HS, FastStart Taq, and Pico Maxx HF significantly increased success rates; Ex Taq HS demonstrated the highest reproducibility.

Conclusions:

• Ex Taq HS, FastStart Taq, and Pico Maxx HF are recommended for initial use to maximize DNA amplification success from highly degraded human samples.
• These polymerases offer improved performance and reproducibility in forensic applications involving compromised DNA.
• The study provides valuable insights for selecting optimal DNA polymerases in challenging forensic casework.