TY - JOUR
T1 - A validation study of the Nucleix DSI-Semen kit - A methylation-based assay for semen identification
AU - Larue, Bobby L.
AU - King, Jonathan L.
AU - Budowle, Bruce
PY - 2013/3/1
Y1 - 2013/3/1
N2 - The detection of semen can assist in reconstructing the events of a sexual assault and impact the outcome of legal dispositions. Many methods currently are used for detecting the presence of semen, but they all have limitations with regards to specificity, sample degradation/consumption, stability of biomolecule assayed, and/or incompatibility with downstream individual identification assays. DNA is routinely collected at sexual assault crime scenes and is widely used for individual identification. The DNA also carries methylation patterns that are tissue specific. To date, however, assays designed to exploit methylation patterns suffer from complex chemistries and unwieldy analyses. DSI-Semen™ kit uses a novel approach involving CpG methylation-sensitive restriction endonuclease digestion coupled to a multiplexed polymerase chain reaction (PCR) to generate an amplicon profile that makes it possible to determine whether the tissue source of a DNA sample was semen or non-semen. The assay returned an appropriate positive result for semen with neat semen, semen stains, and semen/non-semen tissue mixtures. The assay is robust and reliable, with a positive result for semen given as little as 31 pg of template DNA input. Low levels of semen were detected in mixtures of semen and other body fluids. UV-exposed samples and those in the presence of limited concentrations of known PCR inhibitors were typeable. The DSI-Semen™ kit provides a reliable tool for the determination of DNA being derived from semen.
AB - The detection of semen can assist in reconstructing the events of a sexual assault and impact the outcome of legal dispositions. Many methods currently are used for detecting the presence of semen, but they all have limitations with regards to specificity, sample degradation/consumption, stability of biomolecule assayed, and/or incompatibility with downstream individual identification assays. DNA is routinely collected at sexual assault crime scenes and is widely used for individual identification. The DNA also carries methylation patterns that are tissue specific. To date, however, assays designed to exploit methylation patterns suffer from complex chemistries and unwieldy analyses. DSI-Semen™ kit uses a novel approach involving CpG methylation-sensitive restriction endonuclease digestion coupled to a multiplexed polymerase chain reaction (PCR) to generate an amplicon profile that makes it possible to determine whether the tissue source of a DNA sample was semen or non-semen. The assay returned an appropriate positive result for semen with neat semen, semen stains, and semen/non-semen tissue mixtures. The assay is robust and reliable, with a positive result for semen given as little as 31 pg of template DNA input. Low levels of semen were detected in mixtures of semen and other body fluids. UV-exposed samples and those in the presence of limited concentrations of known PCR inhibitors were typeable. The DSI-Semen™ kit provides a reliable tool for the determination of DNA being derived from semen.
KW - CpG methylation
KW - Degraded DNA
KW - Forensic DNA analysis
KW - Forensic tissue typing
KW - Methylation patterns
KW - Semen
KW - Sexual assault
UR - http://www.scopus.com/inward/record.url?scp=84879505808&partnerID=8YFLogxK
U2 - 10.1007/s00414-012-0760-0
DO - 10.1007/s00414-012-0760-0
M3 - Article
C2 - 22895803
AN - SCOPUS:84879505808
VL - 127
SP - 299
EP - 308
JO - International Journal of Legal Medicine
JF - International Journal of Legal Medicine
SN - 0937-9827
IS - 2
ER -