2012 Volume 17 Issue 1 Pages 15-26
We compared automated DNA extraction instruments of AutoMate Express, EZ1 Advanced XL, Maxwell 16 and QIAcube for forensic purpose. DNA was extracted from fresh bloodstains and fresh diluted bloodstains on cotton and denim, three 3-mm punches of FTA card containing buccal cells collected by EasiCollect, and head hair roots and shafts. The genomic and mitochondrial DNA was quantified by real-time PCR assay using D17Z1 locus and/or the C region of hyper variable region 1 (HV1). The extracted DNA was used to amplify 15 STR loci of Identifiler kit and/or the A and the C regions in HV1.
AutoMate Express tended to give the highest DNA concentration from all the samples except for FTA cards and hair roots. Full STR profiles were obtained using all the instruments from bloodstains on cotton and denim, FTA cards and hair roots. Out of the 15 diluted bloodstain samples on cotton and denim, full STR profiles were obtained from 14 and 15 samples for AutoMate Express, 11 and 14 samples for EZ1 Advanced XL, 0 and 6 samples for Maxwell 16, and 8 and 14 samples for QIAcube, respectively. When 20 μl of the denim extract was concentrated and amplified with 1 ng of 9947A DNA, PCR inhibition was slightly observed using AutoMate Express and Maxwell 16, but not observed when using EZ1 Advanced XL and QIAcube.
When the A and the C regions of HV1 were amplified using 2,000 copies of the hair root DNA extracted by all the instruments, positive bands were observed from almost all the samples. On the other hand, when 2,000 copies or less of the hair shaft DNA were amplified, the bands of the A region were weaker than those of the C region for all the instruments especially for AutoMate Express.
In conclusion, AutoMate Express and EZ1 Advanced XL are suitable for DNA extraction from forensic samples, since they are easier to operate than QIAcube is, and they give higher DNA yield than Maxwell 16 does.
