Utilizing DNA analysis to combat the world wide plague of present day slavery--trafficking in persons.

A study was conducted to determine if modern forensic DNA typing methods can be properly employed throughout the world with a final goal of increasing arrests, prosecutions, and convictions of perpetrators of modern day trafficking in persons while concurrently reducing the burden of victim testimony in legal proceedings. Without interruption of investigations, collection of samples containing DNA was conducted in a variety of settings. Evidentiary samples were analyzed on the ANDE Rapid DNA system. Many of the collected swabs yielded informative short tandem repeat profiles with Rapid DNA technology.

Re-assessment of the cut-off levels of Carbohydrate Deficient Transferrin (CDT) for automated immunoassay and multi-capillary electrophoresis for application in a forensic context.

BACKGROUND: The determination of Carbohydrate Deficient Transferrin (CDT) in a forensic context should be based on the use of a screening technique followed, for the "positive samples", by a confirmatory technique. The aim of this study was to compare the two most used automated screening methods for CDT analysis, immuno-nephelometric assay (INA) and multi-capillary electrophoresis (mCE), with a validated HPLC procedure, used as confirmation test, in order to re-evaluate the cut-off concentrations of the screening methods. METHODS: 195 serum samples underwent CDT analysis by using the N Latex CDT direct immuno-nephelometric assay, the multicapillary system Capillarys™ and an anion exchange HPLC method with UV-visible detection at 460nm developed and validated at our laboratories. Statistical analyses were performed by using Bland-Altman plots and ROC curves. RESULTS AND DISCUSSION: The 95% limits of agreement were ±0.94% when comparing INA and HPLC and ±0.60% when comparing mCE and HPLC. The ROC analysis of both INA and mCE, using HPLC as the reference method, showed that no false negative results were found when the cut-off was fixed to 1.2% for mCE and to 2.3% for INA. CONCLUSIONS: The study showed a good agreement among CDT determinations carried out either with mCE or INA or HPLC. However, the usual cut-offs of both mCE (1.3%) and INA (2.5%) should be lowered to minimize false negatives at the screening analysis.

Improved capillary electrophoresis determination of carbohydrate-deficient transferrin including on-line immunosubtraction.

The instrumental analysis of carbohydrate-deficient transferrin (CDT), a recognized marker of chronic alcohol abuse, is most commonly carried out by high-performance liquid chromatography (HPLC) or capillary zone electrophoresis (CZE). Between these two techniques, CZE shows higher efficiency and productivity, but is often reported to be inferior to HPLC in terms of selectivity, because of a less specific ultraviolet detection wavelength than HPLC. On these grounds, the present work was aimed at the development of an improved CZE method for CDT determination, including an on-line immunosubtraction step specifically aimed at enhancing the analytical specificity of CZE determination. The analytical conditions were as follows: uncoated fused silica capillary, 30 microm x 60 cm (L = 50 cm to detector); running buffer, 100 mmol/L borate and 6 mmol/L DAB (1,4-diaminobutane), pH 8.3; voltage, 30 kV; temperature, 25 degrees C; detection, 200 nm. Under the described CZE conditions, a baseline separation between all the CDT related peaks was achieved with good analytical performances in terms of both precision and accuracy. In order to achieve unequivocal recognition of the CDT peaks, an in-capillary immunosubtraction step was included by loading a plug of anti-human transferrin antibody solution after the sample plug. This analytical approach was applied successfully to recognize CDT peaks in the presence of potential interferences.

DNA analysis of digested tomato seeds in stomach contents.

Examination of stomach contents is one of the important steps in medical legal autopsy. Vegetative materials such as stems, roots, and seeds in stomach contents can be valuable evidence for providing investigative leads in death investigation. Currently, the identification of plant materials relies on microscopic and morphologic examination. We have found that many seeds are often protected from acid degradation during stomach digestion by their tough exterior seed coat. Tomato seeds were selected as a model system to assess DNA analysis and plant variety marker identification. The DNA-amplified fragment length polymorphism method was performed to determine if the DNA obtained from single seeds could be used for PCR analysis. From the amplified fragment length polymorphism results, some candidate markers for individualizing seeds from morphologically distinct tomatoes were identified. These data on DNA analysis of tomato seeds indicate amplified fragment length polymorphism is a viable procedure for the individualization of seeds from stomach contents in forensic investigations.

DNA analysis of ingested tomato and pepper seeds.

Ingested food is one of the important types of forensic evidence obtained during a medicolegal autopsy. Many materials containing seeds pass through the human digestive system and are still recognizable; thus, they can be valuable for providing investigative leads. Currently, the identification of seeds relies on microscopic and morphologic examination. However this method sometimes can be problematic. For example, the microscopic appearance of the ingested tomato and pepper seeds is very similar; thus, it is not always easy to distinguish these seeds by comparing their physical characteristics. Tomato and pepper seeds were selected as a model system to assess the value of performing DNA analysis as an alternate and/or complimentary means of seed identification. Results of blind testing indicate that the deoxyribonucleic acid-amplified fragment length polymorphism (DNA-AFLP) results were able to discriminate between pepper and tomato seed samples after they passed through the digestive system.

Forensic botany: using plant evidence to aid in forensic death investigation.

Forensic botany is still an under-utilized resource in forensic casework, although it has been used on occasion. It is an area of specialty science that could include traditional botanical classification of species, DNA, or materials evidence (trace and transfer evidence), crime mapping or geo-sourcing, all dependent on the specific case application under consideration. Critical to the evaluation of plant evidence is careful collection, documentation, and preservation for later scientific analysis. This article reviews proper procedures and recent cases where botanical evidence played a role in establishing either manner or time of death. Plant evidence can be useful for determining if a death was due to an accident, suicide, or homicide, or what time of year burial may have taken place. In addition, plant evidence can be used to determine if a crime scene is a primary or secondary scene and to locate missing bodies.