NCJ Number
222158
Journal
Journal of Forensic Sciences Volume: 53 Issue: 1 Dated: January 2008 Pages: 125-134
Date Published
January 2008
Length
10 pages
Annotation
This paper describes the validation work performed by the Minnesota Bureau of Criminal Apprehension Forensic Science Laboratory for the implementation of the AmpF/STR Yfiler kit (Applied Biosystems in Foster City, CA) in forensic casework.
Abstract
The validation studies found that the Yfiler kit is extremely sensitive, does not exhibit cross-reactivity with female DNA, successfully types male DNA in the presence of overwhelming amounts of female DNA, and is successful in typing actual forensic samples from adjudicated cases. The study shows that 0.125 ng of male DNA will generate a complete 17-locus profile and that as little as 0.06 ng of male DNA yields an average of 9 loci. In the male-male mixtures, a complete profile from the minor component was detected up to a 1:5 ratio; most of the alleles of the minor component were detected at a 1:10 ratio, and more than half of the alleles of the minor component were detected at a 1:20 ratio. Complete YSTR profiles were obtained when 500 pg male DNA was mixed with female DNA at ratios up to 1:1000. At ratios of 1: 5,000 and 1:10,000 (male DNA to female DNA) inhibition of the YSTR amplification was evident. The YSTR results obtained for the adjudicated case samples gave significantly more probative information than the autosomal results. Blood samples were collected by venipuncture in EDTA tubes, and bloodstains were prepared by spotting the blood on S&S paper (Schleicher and Schuell, Keene, NH) and allowing it to air dry. Saliva samples were collected by swabbing the inside of the donor's mouth with a sterile cotton swab and allowing the swab to air dry. In order to obtain a high quantity of female DNA, volunteers spit large volumes of saliva into sterile polypropylene tubes for direct extraction. 4 tables, 6 figures, and 156 references