NCJ Number
232670
Journal
Forensic Science International: Genetics Volume: 4 Issue: 5 Dated: October 2010 Pages: 292-304
Date Published
October 2010
Length
13 pages
Annotation
This article describes the optimization and validation of the original automated DNA extraction protocol.
Abstract
A semi-automated DNA extraction process for casework samples based on the Promega DNA IQ system was optimized and validated on TECAN Genesis 150/8 and Freedom EVO robotic liquid handling stations configured with fixed tips and a TECAN TE-Shake unit. The use of an orbital shaker during the extraction process promoted efficiency with respect to DNA capture, magnetic bead/DNA complex washes and DNA elution. Validation studies determined the reliability and limitations of this shaker-based process. Reproducibility with regards to DNA yields for the tested robotic workstations proved to be excellent and not significantly different than that offered by the manual phenol/chloroform extraction. DNA extraction of animal:human blood mixtures contaminated with soil demonstrated that a human profile was detectable even in the presence of abundant animal blood. For exhibits containing small amounts of biological material, concordance studies confirmed that DNA yields for this shaker-based extraction process are equivalent or greater to those observed with phenol/chloroform extraction as well as our original validated automated magnetic bead percolation-based extraction process. Our data further supports the increasing use of robotics for the processing of casework samples. Figures, tables, appendix, and references (Published Abstract)