The work presented in this thesis uses contemporary methodology to address three gaps in the current understanding of forensic DNA profiling. Preliminary work was undertaken to identify the most appropriate techniques for use in this thesis, given the equipment available. It was discovered that the QIAamp DNA mini kit was suitable for DNA extraction from most sample types. PicoGreen dsDNA quantitation reagent was proven adequate for quantitation of DNA concentrations greater than 5ng/μl and the AmpFlSTR® SGM Plus™ PCR Amplification system was used for all DNA profile generation. These methods were then used to investigate the effect of peri-mortem blood transfusion on DNA profiling. It was hypothesised that donor leucocytes present in the administered blood products could result in mixed DNA profile generation in post-transfusion blood samples. This hypothesis is rejected after direct analysis of blood products and case examples. The second question addresses the preservation of field-collected biological samples for disaster victim identification using DNA analysis. Two buffer solutions are tested for their ability to preserve soft tissue samples over a period of six months at room temperature. The results of DNA quantification and degradation analysis suggest that both solutions are capable of DNA preservation of 5 – 1000mg muscle tissue over a six month time period, allowing full standard DNA profile production. Finally, this thesis examines the normal background level of non-self DNA present on the adult neck surface by sampling 24 volunteers. These observations are used to investigate whether background levels of non-self DNA interfere with DNA profile analysis and interpretation of physical assault situations. The results do not provide a conclusive answer, but augment our understanding of DNA transfer theory by highlighting the high level of non-self DNA normally present on the adult neck due to adventitious transfer, and the discrepancies from previously published DNA transfer theory
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