title: Fast and simple DNA extraction from saliva and sperm cells obtained from the skin or isolated from swabs.
abstract: The forensic scientist often has to cope with problematic samples from the crime scene due to their minute size and thus the low amount of extractable DNA. The retrieval of DNA from swabs taken from the surface of the skin, for example, in cases of strangulation, can be especially difficult. We systematically investigated swabs taken from the skin (to obtain a genetic profile from the victim and also from a possible offender) and from sperm cell containing swabs using two extraction kits: the Invisorb forensic and the Invisorb spin swab kit (both Invitek, Germany). DNA quality and quantity were tested on ethidium bromide containing agarose gels and in a highly sensitive duplex-PCR, which amplifies fragments specific for mitochondrial and nuclear DNA. Absolute quantification was done using real time PCR. Samples, which were positive in the duplex-PCR, were also employed to genetic fingerprinting using the Powerplex ES and the AmpFlSTRIdentifiler(TM) kits. Our study shows that the easy-to-use Invisorb spin swab kit is very suitable for DNA isolation from swabs taken from the skin and also from sperm cells. Retrieval of cells from the skin with swabs moistened in extraction buffer, not in distilled water, led to a significant higher DNA yield.
authors.affiliation: Department of Legal Medicine, Christian-Albrechts-University of Kiel, Germany. nvonwurmb@rechtsmedizin.uni-kiel.de
authors.forename: Nicole
authors.initials: N
authors.lastname: von Wurmb-Schwark
authors.forename: Victoria
authors.initials: V
authors.lastname: Mályusz
authors.forename: Heike
authors.initials: H
authors.lastname: Fremdt
authors.forename: Christine
authors.initials: C
authors.lastname: Koch
authors.forename: Eva
authors.initials: E
authors.lastname: Simeoni
authors.forename: Thorsten
authors.initials: T
authors.lastname: Schwark
mesh_terms: D004247:DNA / Q000302:isolation & purification*; D016172:DNA Fingerprinting / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D011902:Rape; D012463:Saliva / Q000737:chemistry*; D012867:Skin / Q000737:chemistry*; D013094:Spermatozoa / Q000166:cytology*
chemical_list: D004247:DNA