STR Profiles from DNA Samples with "Undetected" or Low Quantifiler™ Results

Abstract:  Screening methods capable of identifying DNA samples that will not yield short tandem repeat (STR) profiles are desired. In the past, quantitation methods have not been sensitive enough for this purpose. In this study, low level DNA samples were used to assess whether Quantifiler™ has a minimum quantitation value below which STR profiles would consistently fail to be detected. Buccal swabs were obtained and the DNA extracted, quantified, and serially diluted to concentrations ranging from 0.002 to 0.250 ng/μL. Samples were analyzed once with Quantifiler™, followed by Profiler Plus™ amplification and capillary electrophoresis analysis. An absolute minimum value below which STR results were unobtainable could not be defined. From the 96 low level samples tested, STR loci (including one full profile) were successfully amplified and detected from 27% of the samples "undetected" by Quantifiler™. However, no STR alleles were detected in 73% of these "undetected" samples, indicating that Quantifiler™ data may be useful for predicting STR typing success.     

The Direction of Violence Against Women Research and Evaluation

Although researchers have made numerous advances in the understanding of the nature, extent, and dynamics of violence against women (VAW), there is an ever-increasing need for data used in academic research and within policy decision-making to be collected via rigorous methodological designs to accurately measure the incidence and impact of VAW. What is now needed are research collaborations within an interdisciplinary research cluster that will expand understanding of the complex nature of VAW. The current article details an agenda or “call to action” to address deficiencies and advance VAW research, in addition to informing VAW intervention and prevention efforts.     

Self-injury group psychotherapy intervention for young offenders: a pilot study

Objective: Self-injury (SI) is a significant and growing problem with the prison estate and a particularly acute issue with young offenders. Despite this, there are no evidence-based interventions for Young Offenders with SI difficulties. The Self-Injury Group Psychotherapy Intervention (SIGPI) was developed to target this.

Method: Drawing on existing evidence, the group was developed and piloted on a sample of 12 male Young Offenders (mean age 19.85 years) in custody with a history of SI. Participants were measured on observable SI behaviour, SI thoughts and urges and psychological distress. A within subject design was utilised with measures at baseline, 6 months and 1 year.

Results: At 12 months follow-up, a significant reduction in SI acts, time spent on SI monitoring, severity of urges and difficulty resisting SI. Psychological distress was also reduced.

Conclusions: SIGPI could be a potentially promising intervention and further investigation into its efficacy is warranted.     

The analysis of an intracerebral hematoma for drugs of abuse

Toxicological investigations were performed on an intracerebral hematoma, antemortem blood, and postmortem blood of an individual who was found unresponsive in his home. The hematoma was found to have ethanol at a concentration of 0.05% (w/v), and benzoylecgonine (a cocaine metabolite) was also confirmed at a concentration of 0.43 mg/L by specific analysis using gas chromatography/mass spectrometry (GC/MS). These results enabled the pathologist to record the cause of death as intracerebral hemorrhage due to acute cocaine intoxication.     

The successful DNA typing of samples following a thermal cycler power loss

An approach for generating DNA profiles when critical samples have been consumed and a power outage occurs during the polymerase chain reaction (PCR) amplification reaction is described. This study demonstrates that a complete and accurate DNA short tandem repeat profile can be obtained: (1) when single source DNA samples are amplified for 26, 27, or 28 cycles using the Profiler Plus and COfiler Amplification Kits after an interruption in amplification, (2) from mock samples when PCR amplification has been interrupted early (after five cycles) or late (after 18 cycles) and the sample is subjected to an additional round of amplification, even after incubation of the sample at room temperature overnight, and (3) from nonprobative casework samples interrupted after approximately 18 cycles of amplification, an overnight incubation at room temperature and subjected to one or two additional rounds of PCR amplification for approximately 26 total cycles. Samples interrupted before five completed cycles and subjected to additional PCR cycles yielded variable results.