Sexual assault evidence often contains sperm cells,which are typically separated from nonsperm cells using manual differential lysis procedures.The goal of this study was to evaluate the automated QIAGEN QIAcube for t...Sexual assault evidence often contains sperm cells,which are typically separated from nonsperm cells using manual differential lysis procedures.The goal of this study was to evaluate the automated QIAGEN QIAcube for this purpose and to compare it to manual QIAGEN and manual organic differential methods using DNA yields and STR profile data for assessment.DNA yields were determined by qPCR,followed by multiplex STR amplification,CE analysis,and mixture interpretation.The automated method was capable of effective cell separation,producing DNA yields sufficient for STR amplification.Further,sperm fraction human:male DNA ratios from the QIAcube samples were consistently closer to the desired 1:1 and STR profiles were less likely to result in mixtures,with 6–8fewer female alleles detected(median 1.5 alleles).Ultimately,using the QIAcube for automated differential processing of semen-containing mixtures reduces the need for downstream mixture interpretation and improves STR profile quality with substantially less hands-on time.展开更多
Due to recent improvements in forensic DNA testing kit sensitivity,there has been an increased demand in the criminal justice community to revisit past convictions or cold cases.Some of these cases have little biologi...Due to recent improvements in forensic DNA testing kit sensitivity,there has been an increased demand in the criminal justice community to revisit past convictions or cold cases.Some of these cases have little biological evidence other than touch DNA in the form of archived latent fingerprint lift cards.In this study,a previously developed optimised workflow for this sample type was tested on aged fingerprints to determine if improved short tandem repeat(STR)profiles could be obtained.Two-year-old samples processed with the optimised workflow produced an average of approximately five more STR alleles per profile over the traditional method.The optimised workflow also produced detectable alleles in samples aged out to 28 years.Of the methods tested,the optimised workflow resulted in the most informative profiles from evidence samples more representative of the forensic need.This workflow is recommended for use with archived latent fingerprint samples,regardless of the archival time.展开更多
文摘Sexual assault evidence often contains sperm cells,which are typically separated from nonsperm cells using manual differential lysis procedures.The goal of this study was to evaluate the automated QIAGEN QIAcube for this purpose and to compare it to manual QIAGEN and manual organic differential methods using DNA yields and STR profile data for assessment.DNA yields were determined by qPCR,followed by multiplex STR amplification,CE analysis,and mixture interpretation.The automated method was capable of effective cell separation,producing DNA yields sufficient for STR amplification.Further,sperm fraction human:male DNA ratios from the QIAcube samples were consistently closer to the desired 1:1 and STR profiles were less likely to result in mixtures,with 6–8fewer female alleles detected(median 1.5 alleles).Ultimately,using the QIAcube for automated differential processing of semen-containing mixtures reduces the need for downstream mixture interpretation and improves STR profile quality with substantially less hands-on time.
基金This work was supported by the Department of Forensic Science of Virgina Commonwealth University and National Institute of Justice(NIJ)Award 2014-DNBX-K013.
文摘Due to recent improvements in forensic DNA testing kit sensitivity,there has been an increased demand in the criminal justice community to revisit past convictions or cold cases.Some of these cases have little biological evidence other than touch DNA in the form of archived latent fingerprint lift cards.In this study,a previously developed optimised workflow for this sample type was tested on aged fingerprints to determine if improved short tandem repeat(STR)profiles could be obtained.Two-year-old samples processed with the optimised workflow produced an average of approximately five more STR alleles per profile over the traditional method.The optimised workflow also produced detectable alleles in samples aged out to 28 years.Of the methods tested,the optimised workflow resulted in the most informative profiles from evidence samples more representative of the forensic need.This workflow is recommended for use with archived latent fingerprint samples,regardless of the archival time.
