The study for the DNA case work sample purification by the automated DNA extraction system with magnetic beads / 中国法医学杂志

ABSTRACT

Objective To evaluate the forensic application of TE-MAGS technology based on magnetic beads kit on TECAN pipetting platform and establish the automated DNA extraction system of case work samples. Methods Sensitivity test 10 different DNA samples from 0.1ng to 1ng were prepared with a commercial standard DNA 9947A diluted into 200μL TES. DNA samples were purified by the TE-MAGS technology automatically on the TECAN pipetting platform and then typed using the IdentifilerTM Kit and get the profile of STR with the software GeneMapper ID-X; the power of purification was tested with a trail that purified 1ng DNA mixed with humus acid and hemachrome. Comparative test 304 casework samples were divided into two purified by TE-MAGS technology and silicon beads respectively to compare the power of purification and the possibility of forensic utility. Results Sensitivity test 0.3ng and more imported DNA can obtain a good quality of DNA profile compared to the lower imported DNA with dropout of STR peaks (0.1ng and 0.2ng). The power of purification of the TE-MAGS technology was not affected by humus acid and hemachrome. The comparison result between automatic TE-MAGS technology and manual silicon beads extraction methods from 304 casework samples showed that the former's success rate(50%) was higher than the latter(40.8%). Conclusion The established DNA purification method of TE-MAGS technology automatic DNA extraction system in this study was obviously advantaging at the aspect of success rate, stability, and uniformity and suited to application in the forensic utility future.