Comparison of Different DNA Extraction Methods for Forensic Samples

Abstract

DNA analyses are important for different types of research in biomedical and forensic science and DNA  isolation is an often required step. Because different DNA isolation kits are constantly becoming available, it is useful to compare their efficacies. This study compared kits of the QIAamp DNA Investigator (Qiagen), ZR Genomic DNA (Zymo Research) and AccuPrep Genomic DNA (Bioneer). Spectrophotometry showed the highest yield of DNA from 200 µl of blood was obtained by the Qiagen kit (5.6 µg) followed by the Bioneer kit (2.74 µg) and Zymo kit (2.39 µg). For purity measured by spectrophotometric A260/A280 nm ratio, DNA isolated by the Qiagen was the most pure and had a ratio of 1.85, closer to the ideal ratio than DNA isolated by Zymo (2.0) and Bioneer (1.03) ratios. Costs of isolation were $3.60/sample for Qiagen, $1.50/sample for Bionner and $0.72 for Zymo kits. The Zymo test took 25 minutes to isolate DNA, the Bioneer kit 35 minutes and the Qiagen kit 50 minutes. These findings may help laboratories select DNA kits that suit their purposes.

Keywords: Forensic science, DNA, extraction, electrophoresis, spectrophotometry, spin-column