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
DNA extraction from degraded skeletal samples is often particularly challenging. The difficulty derives from the fact that variable environment has a significant effect on DNA preservation. During the years 2002-2015 ...DNA extraction from degraded skeletal samples is often particularly challenging. The difficulty derives from the fact that variable environment has a significant effect on DNA preservation. During the years 2002-2015 unidentified degraded skeletal remains were accumulated at our institute, National Institute of Forensic Medicine (NIFM), most of them with none or partial DNA profile. As new methods rapidly emerge, we revisited these samples with partial DNA profiles in the hope to add additional alleles and eventually be able to identify these previously unidentifiable samples. We have chosen to use these samples to compare two automated methods: Prepfiler Express BTA (Applied Biosystems) and QIAcube (Quiagen), in hope of acquiring a more complete DNA profile and eventually make new identifications possibly comparing these profiles with missing person database. In both methods, a preparation step is required, after which the samples undergo automatic DNA extraction. The two protocols are based on different extraction methods. Fresh or non-problematic bone samples as the positive control gave the same results in both methods. In the degraded skeletal samples, the results were significantly better using the QIAcube method in our hands, but since degraded samples are highly variable the combination of both methods could be useful to receive better and more reliable profiles.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.
文摘DNA extraction from degraded skeletal samples is often particularly challenging. The difficulty derives from the fact that variable environment has a significant effect on DNA preservation. During the years 2002-2015 unidentified degraded skeletal remains were accumulated at our institute, National Institute of Forensic Medicine (NIFM), most of them with none or partial DNA profile. As new methods rapidly emerge, we revisited these samples with partial DNA profiles in the hope to add additional alleles and eventually be able to identify these previously unidentifiable samples. We have chosen to use these samples to compare two automated methods: Prepfiler Express BTA (Applied Biosystems) and QIAcube (Quiagen), in hope of acquiring a more complete DNA profile and eventually make new identifications possibly comparing these profiles with missing person database. In both methods, a preparation step is required, after which the samples undergo automatic DNA extraction. The two protocols are based on different extraction methods. Fresh or non-problematic bone samples as the positive control gave the same results in both methods. In the degraded skeletal samples, the results were significantly better using the QIAcube method in our hands, but since degraded samples are highly variable the combination of both methods could be useful to receive better and more reliable profiles.
