Use of RGB values in the Periodic Acid-Schiff color test to determine the presence of vaginal fluid.

This study demonstrates how RGB color values from microscopic smears stained with the Periodic Acid-Schiff reagent under standardized microscopy conditions can be used to indicate the presence of vaginal secretions. Based on data obtained in the study, a numeric threshold determined from the sum of separate values for red, blue and green was determined to differentiate vaginal-based samples with other body fluids. Using this threshold, 55 of 57 vaginal-based samples tested positive for the presence of vaginal secretion.

Mandatory certification of forensic science practitioners in the United States: A supportive perspective.

The article presented is supportive of mandatory certification of forensic scientists and believes that such a mandate can help establish a threshold for competency in the profession, provide a universal standard for ethical professional conduct, and enhance the credibility of forensic science in users of the profession and the general societal public. After examining the history of professional certification in the United States across a spectrum of professions including forensic science, results of surveys sent to forensic science practitioners to gauge their views on mandatory certification is discussed. Seventy-three surveys were received with most surveyors being in support of mandatory certification related to their discipline.

Identifying PCP and four PCP analogs using the gold chloride microcrystalline test followed by raman microspectroscopy and chemometrics.

Identifying drug analogs can be a vexing problem for forensic scientists particularly in today's evolving drug market. This study proposes a method that utilizes microcrystalline tests, Raman microspectroscopy, and chemometrics to help solve this problem. In the present case, the method described was used to clearly differentiate and identify phencyclidine (PCP) and four of its analogs, namely tenocyclidine (TCP), rolicyclidine (PCPy), 3-methoxy phencyclidine (3-MeO PCP), and 4-methoxy phencyclidine (4-MeO PCP).

Detection of prostate specific antigen and salivary amylase in vaginal swabs using SERATEC® immunochromatographic assays.

Immunochromatographic assays are used by crime laboratories to conduct simple and quick analyses of bodily fluids. These streamlined tests are ideal for decreasing the sexual assault kit backlog in the United States. A large-scale analysis of the frequency of positive results of amylase and prostate specific antigen (PSA) endogenously found in the vaginal cavity was conducted using the SERATEC PSA Semiquant and Amylase tests.

Development of a multiplex, PCR-based genotyping assay for African and Asian elephants for forensic purposes.

Wildlife crimes and the threats they present to elephant populations raise the need to develop and implement DNA-based methodology as an aid for wildlife forensic investigations and conservation efforts. This study describes the development of a tetra-nucleotide repeat STR multiplex, genotyping assay that will identify Asian elephant (Elephas maximus) and African elephant (Loxodonta africana) DNA. The assay targets six tetra-nucleotide STRs and two sex-typing markers simultaneously in both genera of elephants, a first for elephant genotyping assays.

High resolution melt curve analysis based on methylation status for human semen identification.

A high resolution melt curve assay to differentiate semen from blood, saliva, urine, and vaginal fluid based on methylation status at the Dapper Isoform 1 (DACT1) gene was developed. Stains made from blood, saliva, urine, semen, and vaginal fluid were obtained from volunteers and DNA was isolated using either organic extraction (saliva, urine, and vaginal fluid) or Chelex 100 extraction (blood and semen). Extracts were then subjected to bisulfite modification in order to convert unmethylated cytosines to uracil, consequently creating sequences whose amplicons have melt curves that vary depending on their initial methylation status.

Detection of male DNA in the vaginal cavity after digital penetration using Y-chromosome short tandem repeats.

In this study, useful genetic information from male donors was obtained on vaginal swabs taken from female volunteers after male digital vaginal penetration in a time frame relevant to a sexual assault investigation. Vaginal swabs were collected from eight volunteers at intervals of 1, 6, 12, 24, and 72 hours after digital vaginal penetration. DNA was extracted from collected swabs and subsequently genotyped using a commercially available Y-chromosome short tandem repeats (Y-STR) multiplex kit.

Comparative forensic soil analysis of New Jersey state parks using a combination of simple techniques with multivariate statistics.

This study has shown that the combination of simple techniques with the use of multivariate statistics offers the potential for the comparative analysis of soil samples. Five samples were obtained from each of twelve state parks across New Jersey in both the summer and fall seasons. Each sample was examined using particle-size distribution, pH analysis in both water and 1 M CaCl2 , and a loss on ignition technique.

The utility of Y-STR profiling in four-, six- and eight-day postcoital vaginal swabs.

Y-STR profiles using the Promega PowerPlex(®) Y system were attempted on multiple vaginal swabs collected at four, six and eight days after intercourse from female partners of 11 couples. At four days postcoitus, full composite profiles (where swabs yielded confirmed alleles at all 11 loci) were obtained for five of the 11 couples and 78% of all possible alleles summed for all couples were confirmed (able to be duplicated in different swabs). Results for composite profiles for all couples taken at six days after intercourse showed that 53% of all alleles summed for all couples were confirmed.

The utility of polyester and cotton as swabbing substrates for the removal of cellular material from surfaces.

Various types of cotton and polyester fabrics were tested to ascertain the optimal physical and chemical characteristics of fabrics needed for the removal of cellular material from surfaces. DNA quantitation values obtained on dried saliva stains showed no difference between cotton and polyester across all constructions and solvent conditions. Fabrics used dry and with water yielded higher quantitation values than those used with isopropanol.

Differentiation of twenty-one glitter lip-glosses by pyrolysis gas chromatography/mass spectroscopy*.

Differentiation of 21 glitter lip-glosses from seven manufacturers was attempted by pyrolysis gas chromatography/mass spectroscopy. Samples were pyrolyzed on a ribbon probe at 800 degrees C for 20 sec and analyzed with an Agilent 6890N Network GC System and Agilent 5973 Network Mass Selective Detector with MSD Productivity ChemStation Data Analysis software. The total ion chromatograms obtained were examined and differences in the presence or absence of certain chromatographic peaks corresponding to certain pyrolysis products (e.

An ELISA method for the identification of salivary amylase.

An ELISA method for the detection of salivary amylase in dried stains using a monoclonal anti-human salivary amylase antibody was developed. Studies demonstrated the assay to be sensitive down to 0.0002 Sigma units and showed a linear response between absorbance and salivary amylase activity between 0.