Defining background DNA levels found on the skin of children aged 0-5 years.

There are currently no data available regarding the normal levels of DNA found on the skin of children engaging in routine day to day activities to assist with the forensic interpretation of DNA profiles generated from skin surface swabs. To address this deficit, skin surface swab samples were collected from 12 face/neck sites and 20 body sites on 50 children less than 5 years old. After exclusion of spoilt samples, 60 sets of swabs from 47 children (30 face/neck, 30 body) comprising of 944 individual samples were analysed.

The effect on cadaver blood DNA identification by the use of targeted and whole body post-mortem computed tomography angiography.

Post-mortem computed tomography angiography (PMCTA) involves the injection of contrast agents. This could have both a dilution effect on biological fluid samples and could affect subsequent post-contrast analytical laboratory processes. We undertook a small sample study of 10 targeted and 10 whole body PMCTA cases to consider whether or not these two methods of PMCTA could affect post-PMCTA cadaver blood based DNA identification.

Anthropological measurement of lower limb and foot bones using multi-detector computed tomography.

Anthropological examination of defleshed bones is the gold standard for osteological measurement in forensic practice. However, multi-detector computed tomography (MDCT) offers the opportunity of three-dimensional imaging of skeletal elements, allowing measurement of bones in any plane without defleshing. We present our experiences of the examination of 15 human lower limbs in different states of decomposition using MDCT.

Investigation into "normal" background DNA on adult necks: implications for DNA profiling of manual strangulation victims.

Others have investigated the role that DNA profiling could play as a method for identifying the perpetrator of manual strangulation. These studies have demonstrated that it is possible to collect offender DNA from the skin surface of a victim following physical contact. It is not known whether nonself biological material is normally present on the skin surface due to adventitious transfer occurring during innocent everyday interactions.

DNA reviews: low level DNA profiling.

Low copy number (LCN) DNA profiling has recently been scrutinized in the United Kingdom following the comments of Mr Justice Weir made during the trial of suspected terrorist Sean Hoey. Mr Hoey was acquitted of all charges related to the Omagh bombing of 1998, following the inadmissibility of key DNA evidence during this trial. The Association of Chief Police Officers and Crown Prosecution Service, initially suspended the use of this technique, but quickly reinstated its use following an internal enquiry.

Cancer and forensic microsatellites.

Although not directly related, circumstances do occur in forensic investigations whereby cancer studies and forensic science cross paths. This review takes a look at the circumstances under which this may occur, and investigates some potential problems that can arise when tumor tissue is submitted for DNA profile analysis. A background to the underlying molecular biology of tumors is described, highlighting the genetic instabilities that are observed in DNA sequences of similar or identical primary structure to the short tandem repeat markers used in forensic DNA profiling kits.

DNA reviews: predicting phenotype.

The prediction of an individuals physical appearance from small biological samples, such as those collected from crime scenes may still sound like science fiction, but how close are we to achieving this goal? This review provides a brief introduction to the areas under investigation for direct and indirect phenotypic inference from DNA alone and suggests some sources of further reading for those interested in gaining a more in-depth knowledge of this complex subject.

DNA reviews: DNA identification following CBRN incidents.

Chemical, biological, radioactive, or nuclear (CBRN) incidents can occur due to accident or deliberate action, and may result in substantial loss of life. Whatever the cause, the requirement for identification of the deceased may necessitate the removal of contaminated samples to a DNA laboratory for processing. This review looks at the potential types of CBRN that may result in the requirement for DNA identification of the deceased and investigates the potential risks and difficulties associated with processing samples of this type.

Sex determination.

Determing the sex of a give DNA sample can provide criminal investigators with useful intelligence and can aid the identification of missing persons and disaster victims. Polymerase chain reaction-based systems that amplify regions of the am elogenin gene have become the method of choice for sex determination of biological samples. This system can, however, result in false female sex designation when mutations affect primer binding sites of the Y homolog of this target sequence, causing drop out of the Y amplification product.

Disaster victim identification.

In the event of any mass fatality incident, despite the cause, disaster victim identification must be undertaken; the humanitarian and legal responsibility for this falls on the forensic community. Mass fatality incidents can be natural (e.g.

How long does it take a static speaking individual to contaminate the immediate environment?

Developments in forensic genetic profiling mean that only a very little DNA is required to generate an identifying profile. However, as this sensitivity increases so does the risk of contamination with non-offender DNA, potentially leading to the conviction of innocents, or release of the guilty. The work of Rutty et al.

Forensic DNA on the internet.

The shear number of websites a vailable addressing the topic of forensic DNA investigation can make the search for specific information time-consuming and frustrating. This review aims to relieve this tension by drawing the reader's attention to a small number of well-produced and maintained websites covering major aspects of the forensic DNA field in genomic and Y chromosome short-tandem repeats and mitochondrial DNA analysis.

Automated DNA profile analysis.

DNA profile analysis is not a simple process. Stringent demands are placed on the accuracy and consistency of forensic evidence so that complex, robust, and reproducible guidelines are necessary to assist the analyst and ensure mistakes are eliminated before a final profile is reported. The guidelines used for forensic DNA profile interpretation are formulated by investigation and statistical evaluation of all aspects of the analytical procedure.

Lab-on-a-chip technology.

The techniques and laboratory processes involved in the production of DNA profiles for forensic applications are well developed, robust, and reliable. Unfortunately, they can now also be considered too slow and expensive to be able to match the ever-increasing demands placed upon them. The most rapid DNA profiling instrumentation in current usage are capillary electrophoresis (CE) systems.

Nonhuman DNA.

DNA has now been used to aid criminal investigation for more than 20 years. The vast majority of this evidence has been produced by profiling of human genetic material. However, DNA profiling technology is not restricted to the human genome.

Mini-STRs.

The use of the short-tandem repeat (STR) as the DNA marker of choice in forensic profiling has lead to the construction of criminal intelligence databases that now contain millions of profiles used in the detection and linking of suspects and scenes. The incredible size and success rate of current systems have ensured that efforts to move away from STR profiling and toward the use of alternate DNA markers are practically impossible, mainly because of the financial implications involved in such a move. Problems are routinely encountered when template DNA is of suboptimal condition, as is commonly the case in the forensic laboratory, whereby full profile generation of degraded samples is not possible.