Isolation and identification of female DNA on postcoital penile swabs

After sexual assault, cells originating from the assailant may be recovered from the victim. Through polymerase chain reaction (PCR)-based technology, positive scientific identification of the assailant may be made from these cells. Described is a prospective study describing a method for positively identifying cells from a female sex partner obtained from postcoital swabs of the penis of the male sex partner. Swabs were taken from the penis of a man at 1- to 24-hour intervals after coitus. DNA was isolated from each swab through standard organic extraction methods. The presence of female DNA was detected using the gender-specific amelogenin marker. Extracted DNA was amplified for eight different genetic loci using the Promega PowerPlex kit (Promega) and Amplitaq Gold (Perkin Elmer). Amplified samples were electrophoresed on precast sequencing gels (Hitachi) and were analyzed fluorescently using Hitachi's FMBIO 2 fluorescent scanner and software. Each sample obtained from a penile swab or condom was compared to male and female buccal controls. Female DNA was isolated from all postcoital penile swabs as determined by exclusive amplification of the X-chromosome specific 212 base pair amelogenin marker. In all cases, scientific identification of the female DNA from the swabs was determined by coamplification of eight STR loci (PowerPlex) and was compared to female and male control profiles. Cells shed from a female victim during sexual intercourse can be retrieved from the penis of a male offender after sexual intercourse during a 1- to 24-hour postcoital interval. DNA can be extracted from these cells and can be used to scientifically identify the female sexual participant through PCR-based technology. It is suggested that penile swabs be taken from alleged perpetrators of sexual assaults to associate them with a female victim.     

Comparison of p30 and acid phosphatase levels in post-coital vaginal swabs from donor and casework studies

The application of p30 detection to casework analysis of seminal traces on vaginal swabs is reported and compared with the levels of acid phosphatase determined.A simple crossed-over immunoelectrophoresis system was used for batch identification of swab extracts using a commercially obtained anti-p30 serum.Positive p30 results were obtained in less than 20% of the casework swab extracts, but they provide conclusive proof of the presence of semen which is a substantial advantage over the quantitative determination of acid phosphatase.     

An evaluation of an enzymatic choline determination for the identification of semen in casework samples

This study compares the detection of choline in seminal stains by both an enzymatic method and by the standard Florence crystal test. The tests were conducted on 293 actual casework samples. In those samples identified as containing semen, choline was detected twice as often by the enzymatic method compared to the Florence method (84.6 versus 40.3%). The choline results were correlated with spermatozoa and acid phosphatase tests. The enzymatic detection of choline in seminal stains was found to be a fast, easy, sensitive, and reliable test.     

Simultaneous identification of alpha-L-fucosidase and phosphoglucomutase (PGM) subtyping in semen stains

Seminal fluid and stains were analyzed by isoelectric focusing to determine the donor phenotype in the alpha-L-fucosidase (AlFuc) polymorphic system. The enzyme is found in both seminal fluid and spermatazoa. Three common phenotypes exist and can be identified in fluid specimens stored at 4 degrees C for more than a year. Untreated semen specimens display more than eight distinct bands of alpha-L-fucosidase activity with isoelectric points of pH 6.6 and below. Neuraminidase-treated specimens have enhanced banding patterns cathodally with a loss of activity in anodal bands making it easier to phenotype specimens. Semen stains maintained in dehumidified chambers at 25 or 37 degrees C retained activity for at least one month and could be accurately phenotyped. Activity was observed in semen specimens maintained at -20 degrees C in the dried state for a period of one year, whereas a complete loss of activity was observed after two weeks in similar specimens maintained at 25 or 37 degrees C under humid conditions. Of seventy-four semen stains analyzed, two had no apparent activity. Of the remaining seventy-two specimens 56, 32, and 12% were phenotyped as FUC 1-1, FUC 2-1, and FUC 2-2, respectively. Calculated gene frequencies are FUC1 = 0.72 and FUC2 = 0.28. Following analysis of alpha-L-fucosidase, the agarose gel can be chemically developed to reveal the PGM1 subtyping pattern. The ability to phenotype both systems in semen stains significantly improves the ability of the analyst to individualize this type of physical evidence. The probability of discrimination for these two combined systems is approximately 0.89.     

An enzyme-linked immunosorbent assay (ELISA) for human semen identification based on a biotinylated monoclonal antibody to a seminal vesicle-specific antigen

Monoclonal antibody mouse antihuman semen-5 (MHS-5) (immunoglobulin G1 [IgG1]) was biotinylated using N-biotinyl-w-aminocaproic acid-N-hydroxysuccinimide ester. This monoclonal antibody-biotin conjugate recognized low molecular weight peptide bands between 10.5 and 20 kilodaltons on immunoblots of liquefied semen. Immunodominant peptides had molecular weights of 10.5, 11.5, and 13.5 kilodaltons. An enzyme-linked immunosorbent assay (ELISA) developed with the biotinylated-MAb and streptavidin peroxidase demonstrated sensitivity curves with lower limits of 10 ng of seminal fluid protein per microtiter well using 50 ng per well of monoclonal antibody-biotin conjugate. Cross-reactivity studies on a panel of human biological fluids and tissues demonstrated no cross-reactivity or false positives using the monoclonal antibody-biotin conjugate. The sensitivity of the monoclonal antibody-biotin ELISA was compared to ELISA based upon a polyclonal secondary antibody-peroxidase conjugate. These findings indicate that this ELISA assay, based on a biotinylated monoclonal antibody to a seminal vesicle-specific antigen, may be useful for semen identification.     

The application of a simple RIA technique for the detection of 19-OH F1 alpha/F2 alpha prostaglandin, a specific semen marker, in semen contaminated vaginal swabs: time since intercourse studies

The specificity of the 19-OH F1 alpha/F2 alpha prostaglandin antisera for the detection of semen in seminal/vaginal mixtures, has been evaluated. Using a parallel curve test we found that the antibody showed a high specificity for these seminal prostaglandins in seminal/vaginal mixtures at concentrations of between 2 pg and 40 pg/100 microliter. The precision of the assay has been improved by the use of a donkey-anti-rabbit ferritin-bound second antibody. The application of this detection system makes it possible to complete an assay within 4.5 h. A survey of 50 semen-free vaginal swabs obtained from 3 donors, taken throughout the menstrual cycle, showed no trace of these prostaglandins. They were also not detected in the vaginal secretions of two further donors who were undergoing medication. Using only 10-microliter aliquots of a seminal/vaginal swab extract, prepared in 500 microliter, it was possible to detect semen up to approx. 80 h after one sexual act.     

Validation of the use of a commercially available kit for the identification of prostate specific antigen (PSA) in semen stains

PSA is currently being used to detect and monitor quantitatively the development of prostate cancer by serum levels of PSA and has also been found to be present in high concentrations in semen. Elegantly simple, sensitive, and reproducible methods have been developed for analysis of the presence of PSA, including the Tandem-E PSA Immunoenzymetric Assay. The most common procedures for the forensic identification of semen have focused on the microscopic detection of sperm, acid phosphatase activity, and immunoelectrophoretic methods for the detection of PSA. Although these methods have been used for many years, there are problems associated with each method. The Tandem-E PSA Immunoenzymetric Assay detected PSA in 100% of the forensic casework fabric samples, 80% of the forensic casework vaginal swabs and 100% of the vasectomized individuals tested. The cut-off value was determined to be 1.77 ng/mL. These results indicate that this method can be used to identify the presence of semen in forensically significant specimens.     

Transferrin (TF) typing from semen stains using isoelectric focusing and immunoblotting: correlation of TF types among blood, semen, urine, and vaginal secretion.

We describe a method for obtaining nondistorted and reproducible transferrin (TF) typing from liquid semen and semen stains. Isoelectric focusing of TF isoproteins on polyacrylamide gel (IEF-PAGE, pH 4 to 6.5) was accomplished using a 0.5 mm thick gel. The separated isoproteins were then visualized by immunoblotting with TF-specific antibody. Pretreatment of semen samples with neuraminidase enhanced the TF band resolution. The method was reliable, sensitive and simple, with a high resolution. When maintained at room temperature, laboratory-prepared semen stains were TF-typable for up to at least 50 weeks. The TF types in semen stains were correlated with the types found in the corresponding blood and urine samples. TF typing could therefore provide an additional discriminant characteristic in the forensic examination of semen stains. An evaluation of TF typing by IEF-PAGE and immunoblotting was also performed on casework samples submitted to our laboratory.     

An evaluation of the effect of incorporating metal salts into 1,8 diazafluoren-9-one (DFO) formulations for fingermark enhancement

A study into the modification of 1,8-diazafluoren-9-one (DFO) formulations by the additions of metal salts into the working solution is reported. Similar additions have been found to increase the fluorescence of marks developed using other amino acid reagents including 1,2-indandione and the ninhydrin analogue 5-methylthioninhydrin. It was found that adding zinc chloride to give a 1:1 ratio of zinc ions:DFO molecules gave optimum fluorescence, and improvements in performance over the standard DFO formulation were achieved. Attempts to produce equivalent formulations with iron, nickel and palladium chlorides were unsuccessful. In a comparative trial with a 1,2-indandione-zinc formulation on brown paper and cardboard substrates, 1,2-indandione-zinc gave superior results and it was decided to focus further research on this reagent instead of DFO-zinc.     

Pneumatic spaces of the zygomatic arch (zygomatic air cell defect) on pantomograms--an aid for age determination and identification

The analysis of panoramic radiographs of the jaws for forensic purposes is well established. The dental findings on the radiographs give valuable information concerning the identity and possible age. Panoramic radiographs also depict the zygomatic arches. Pneumatized spaces of the temporal bone's zygomatic arch process are asymptomatic variations, entitled "zygomatic air cell defect" (ZACD). Data on ZACD prevalence might support the current forensic-odontologic practice in the fields of identification and age assessment. The authors analyzed 6 studies subjected to evaluate ZACD on panoramic radiographs. The out-patients were subjected to systematic radiography prior to treatment planning in specialized dental or maxillofacial surgery clinics. The age of the 7870 patients varied between 6 and 97 years. ZACD was found in 169 patients (prevalence: 2.32%; female: 56.12%, male: 43.9%). Most ZACD were unilateral (70%). In these studies no ZACD occurred in children younger than 7 years of age. There was no statistically significant difference concerning ZACD prevalence in the sub-groups of children aged 9 to 13 vs. 14 to 17 years. This review demonstrates the prevalence of ZACD on orthopantomograms. The prevalence of this finding in the investigated children does not differ from the prevalences reported for adults, and is low in general. The presence of ZACD in persons might be valuable for the identification of humans or human remains and for age estimation in addition to other physical and dental findings.     

A possibility for identification of the knife's edge in stab wounds (author's transl)

It is known from forensic-medical practice that the wound track of stab wounds reflects the form and dimensions of the knife's edge, when there are no supplementary cuts. If the wound channel passes through compact organs (liver, kidney, spleen, etc) it can be exposed for direct observation by removing one of its sides which allows observation of the approximate form and dimensions of the knife's edge. It enables eliminatione of those weapons which do not fit. A case of homicide is described with 9 stab wounds, one of which penetrating the liver, where the above described method was successfully used. A case of an adult man's murder is described with 9 puncture wounds, one of which penetrating the liver, where the above described method was successfully used. A case of an adult man's murder is described with 9 puncture wounds, one of which penetrating the liver, where the above described method has been successfully applied.     

An aqueous-organic extraction method for the isolation and identification of psilocin from hallucinogenic mushrooms

A simple aqueous extraction method for the isolation and identification of psilocin from Psilocybe cubensis mushrooms is reported. This method employs a dephosphorylation of the phosphate ester to psilocin, which facilitates a greater product yield and simplifies identification. Psilocin extracted by this method is sufficiently concentrated and free of cocontaminants to allow identification by infrared spectroscopy and gas chromatography/mass spectrometry.     

Facial soft tissue depths in craniofacial identification (part II): An analytical review of the published sub-adult data

Prior research indicates that while statistically significant differences exist between subcategories of the adult soft tissue depth data, magnitudes of difference are small and possess little practical meaning when measurement errors and variations between measurement methods are considered. These findings raise questions as to what variables may or may not hold meaning for the sub-adult data. Of primary interest is the effect of age, as these differences have the potential to surpass the magnitude of measurement error. Data from the five studies in the literature on sub-adults which describe values for single integer age groups were pooled and differences across the ages examined. From 1 to 18 years, most soft tissue depth measurements increased by less than 3 mm. These results suggest that dividing the data for children into more than two age groups is unlikely to hold many advantages. Data were therefore split into two groups with the division point corresponding to the mid-point of the observed trends and main data density (0-11 and 12-18 years; division point = 11.5 years). Published sub-adult data for seven further studies which reported broader age groups were pooled with the data above to produce the final tallied soft tissue depth tables. These tables hold the advantages of increased sample sizes (pogonion has greater than 1770 individuals for either age group) and increased levels of certainty (as random and opposing systematic errors specific to each independent study should average out when the data are combined).     

Facial soft tissue depths in craniofacial identification (part I): An analytical review of the published adult data

With the ever increasing production of average soft tissue depth studies, data are becoming increasingly complex, less standardized, and more unwieldy. So far, no overarching review has been attempted to determine: the validity of continued data collection; the usefulness of the existing data subcategorizations; or if a synthesis is possible to produce a manageable soft tissue depth library. While a principal components analysis would provide the best foundation for such an assessment, this type of investigation is not currently possible because of a lack of easily accessible raw data (first, many studies are narrow; second, raw data are infrequently published and/or stored and are not always shared by some authors). This paper provides an alternate means of investigation using an hierarchical approach to review and compare the effects of single variables on published mean values for adults whilst acknowledging measurement errors and within-group variation. The results revealed: (i) no clear secular trends at frequently investigated landmarks; (ii) wide variation in soft tissue depth measures between different measurement techniques irrespective of whether living persons or cadavers were considered; (iii) no clear clustering of non-Caucasoid data far from the Caucasoid means; and (iv) minor differences between males and females. Consequently, the data were pooled across studies using weighted means and standard deviations to cancel out random and opposing study-specific errors, and to produce a single soft tissue depth table with increased sample sizes (e.g., 6786 individuals at pogonion).     

The specificity of electron impact mass spectroscopy for the identification of N-ethyl-1-phenylcyclohexylamine (PCE)

The electron impact mass spectrum of N-ethyl-1-phenylcyclohexylamine (PCE) was studied using both deuterium-labeled compounds and structurally related analogs. The deuterium-labeled compounds used were d2 . PCE with two deuterium atoms on the methylene carbon of the N-ethyl group, d3 . PCE with three deuterium atoms on the methyl carbon of the N-ethyl group, d4 . PCE with four deuterium atoms on the beta carbons of the cyclohexyl rings, and d5 . PCE with five deuterium atoms on the phenyl ring. Structurally related compounds used included the N,N-dimethyl, N-propyl, and cyclopentyl analogs. The identities of some major fragments and possible pathways leading to their formation are shown. Electron impact mass spectroscopy is shown to be a definitive test for the identification of PCE.     

Performance evaluation of the Scent Transfer Unit (STU-100) for organic compound collection and release

The Scent Transfer Unit (STU-100) is a portable vacuum that uses airflow through a sterile gauze pad to capture a volatiles profile over evidentiary items for subsequent canine presentation to assist law enforcement personnel. This device was evaluated to determine its ability to trap and release organic compounds at ambient temperature under controlled laboratory conditions. Gas chromatography-mass spectrometry (GC-MS) analyses using a five-component volatiles mixture in methanol injected directly into a capture pad indicated that compound release could be detected initially and 3 days after the time of collection. Additionally, 15 compounds of a 39-component toxic organic gaseous mixture (10-1000 parts per billion by volume [p.p.b.(v)]) were trapped, released, and detected in the headspace of a volatiles capture pad after being exposed to this mixture using the STU-100 with analysis via GC-MS. Component release efficiencies at ambient temperature varied with the analyte; however, typical values of c. 10% were obtained. Desorption at elevated temperatures of reported human odor/scent chemicals and colognes trapped by the STU-100 pads was measured and indicated that the STU-100 has a significant trapping efficiency at ambient temperature. Multivariate statistical analysis of subsequent mass spectral patterns was also performed.     

Scent identification evidence in jurisdiction (drawing on the example of judicial practice in Poland)

One of the most significant challenges for contemporary forensic science seems to be research of new sources of physical evidence. Particularly after successful implementation of revolutionary DNA identification law enforcement agencies look for other new and perhaps more efficient techniques.