Method to predict the chance of developing a male profile out of mixtures of male and female DNA

Laberke, Patrick; Grossenbacher, R.; Hausmann, Roland; Balitzki, Beate

doi:10.1007/s00414-011-0615-0

Cited by 2 publications

(1 citation statement)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The goal of the crime laboratory processing such swabs is to obtain pure male DNA from the mixture of sperm from the assailant and epithelial cells from the victim in order to profile the male DNA with autosomal markers and to identify the perpetrator. Y chromosomal STR markers can be analyzed from a mixture of male and female DNA [2-6], but Y profiles do not determine the identity of the rapist because all males of the same paternal lineage have the same Y profile. Furthermore, Y chromosome profiles of unpurified DNA cannot be used when the victim is male.…”

Section: Introductionmentioning

confidence: 99%

Isolating DNA from sexual assault cases: a comparison of standard methods with a nuclease-based approach

Garvin¹,

Fischer

Schnee-Griese

et al. 2012

Invest Genet

View full text Add to dashboard Cite

BackgroundProfiling sperm DNA present on vaginal swabs taken from rape victims often contributes to identifying and incarcerating rapists. Large amounts of the victim’s epithelial cells contaminate the sperm present on swabs, however, and complicate this process. The standard method for obtaining relatively pure sperm DNA from a vaginal swab is to digest the epithelial cells with Proteinase K in order to solubilize the victim’s DNA, and to then physically separate the soluble DNA from the intact sperm by pelleting the sperm, removing the victim’s fraction, and repeatedly washing the sperm pellet. An alternative approach that does not require washing steps is to digest with Proteinase K, pellet the sperm, remove the victim’s fraction, and then digest the residual victim’s DNA with a nuclease.MethodsThe nuclease approach has been commercialized in a product, the Erase Sperm Isolation Kit (PTC Labs, Columbia, MO, USA), and five crime laboratories have tested it on semen-spiked female buccal swabs in a direct comparison with their standard methods. Comparisons have also been performed on timed post-coital vaginal swabs and evidence collected from sexual assault cases.ResultsFor the semen-spiked buccal swabs, Erase outperformed the standard methods in all five laboratories and in most cases was able to provide a clean male profile from buccal swabs spiked with only 1,500 sperm. The vaginal swabs taken after consensual sex and the evidence collected from rape victims showed a similar pattern of Erase providing superior profiles.ConclusionsIn all samples tested, STR profiles of the male DNA fractions obtained with Erase were as good as or better than those obtained using the standard methods.

show abstract

Section: Introductionmentioning

confidence: 99%