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.     

Evaluation of prostate-specific antigen (PSA) membrane test assays for the forensic identification of seminal fluid.

Prostate specific antigen (PSA, also known as p30), a glycoprotein produced by the prostatic gland and secreted into seminal plasma, is a marker used for demonstrating the presence of seminal fluid. Methods for the detection of PSA include Ouchterlony double diffusion, crossover electrophoresis, rocket immuno-electrophoresis, radial immunodiffusion, and ELISA. The extremely sensitive ELISA technique can detect PSA in concentrations as low as approximately 4 ng/mL. However, all these techniques are cumbersome and time consuming to perform in forensic laboratories, especially when only a few samples per week are processed. Various membrane tests are currently used in clinical settings to screen a patient's serum for the presence of PSA at levels greater than 4 ng/mL. In this study we evaluated three immunochromatographic PSA membrane tests by analyzing semen stains stored at room temperature for up to 30 years, post-coital vaginal swabs taken at different time after intercourse, semen-free vaginal swabs, and various female and male body fluids, including urine. The data demonstrate that PSA membrane test assays offer the same sensitivity as ELISA-based tests and provide a rapid approach for the forensic identification of seminal fluid. Furthermore, when the supernatant from a DNA extraction is used for the assay, there is essentially no DNA consumption for determining the presence of PSA in a forensic sample.     

Optimisation of choline testing using Florence Iodine reagent,including comparative sensitivity and specificity with PSA and AP tests

The detection of semen in forensic science is essential in cases of sexual assault but can be problematic in the absence of spermatozoa. Choline is known to occur in high concentrations in seminal fluid and the Florence Iodine test for its detection has been used in forensic science for many years, however very little is documented regarding its sensitivity and specificity in forensic casework. This paper describes the optimisation of the choline Florence Iodine test (FI) and investigates the sensitivity and specificity of the test against different body fluids, food and drink substances, cleaning products and laboratory chemicals. Comparative testing against Acid Phosphatase (AP) and Prostate Specific Antigen (PSA Seratec®) tests is described and shows that the FI test has greater specificity than the PSA test which cross reacts with a number of body fluids.     

The detection of protein p30 in seminal stains by means of thin-layer immunoassay

The detection of p30 by means of an indirect thin-layer immunoassay (TIA) is described. Extracts from 20 samples can be analyzed in approximately 2 h with a detection limit of approximately 50 ng. The p30 protein was detected in seminal stains which had been stored at room temperature for six months and at 130 degrees C for 4 h. Blood, saliva, urine, perspiration, and tears did not interfere with the method. The reliability of the method was demonstrated in a blind study.     

用酶标抗人精液单克隆抗体A_(10)C_6建立ELISA斑点法快速鉴定人精(液)斑

作者用过氧化物酶标记自己研制的抗人精液单克隆抗体A10C6建立了简便快速鉴定人精斑的ELISA斑点法，直接通过酶标抗体上的酶催化底物显示颜色变化，来判断结果，阳性呈灰色斑点，阴性为无色。其结果只对人精斑浸出液显示阳性斑点，对人的其他组织器官及体液均呈阴性，对动物精斑也无交叉反应，精斑浸出液稀释到1：3200倍仍呈阳性结果。     

Segmental hair analysis can demonstrate external contamination in postmortem cases

Excluding laboratory mistakes, a false positive hair result can be observed in case of contamination from environmental pollution (external contamination) or after drug incorporation into the hair from the individual body fluids, such as sweat or putrefactive fluid (post mortem artifact). From our 20 years experience of hair testing, it appears that artifact(s) cannot be excluded in some post mortem cases, despite a decontamination procedure. As a consequence, interpretation of the results is a challenge that deserves particular attention. Our strategy will be reviewed in this paper, based on six cases. In all cases, a decontamination procedure with two washes of 5 ml of dichloromethane for 5 min was performed and the last dichloromethane wash was negative for each target drug. From the histories, there was no suspicion of chronic drug use. In all six cases, the concentrations detected were similar along the hair shaft, irrespective of the tested segment. We have considered this as indicative of external contamination and suggested to the forces or the judges that it is not possible to indicate exposure before death. In contrast to smoke, it seems that contamination due to aqueous matrices (sweat, putrefactive fluid, blood) is much more difficult to remove. To explain potential incorporation of 7-aminoflunitrazepam via putrefactive material, the author incubated negative hair strands in blood spiked at 100 ng/ml and stored at +4°C, room temperature and +40 °C for 7, 14 and 28 days. After routine decontamination, 7-aminoflunitrazepam tested positive in hair, irrespective of the incubation temperature, as early as after 7 days (233-401 pg/mg). In all periods, maximum concentrations were observed after incubation at room temperature. The highest concentration (742 pg/mg) was observed after 28 days incubation at room temperature. It is concluded that a standard decontamination procedure is not able to completely remove external contamination in case of post mortem specimens. Homogenous segmental analyses can be probably indicative of external contamination and therefore a single hair result should not be used to discriminate long-term exposure to a drug. Nor should the presence of a metabolite be considered as a discrimination tool, as it can also be present in putrefactive material.     

alpha-L-fucosidase phenotyping in human placentae, semen and seminal stains

The polymorphism of alpha-L-fucosidase (Fu) was investigated in a Japanese population from samples of placentae and semen, using isoelectric focusing. The gene frequencies of placental types were Fu1 = 0.748 and Fu2 = 0.252, and those of seminal types were Fu1 = 0.739 and Fu2 = 0.261. The coincidence in the distribution between the placental and seminal types suggests that the Fu types occurring in placentae and in semen are controlled by the same Fu alleles. The Fu typing was possible in seminal stains stored at 4 degrees C for up to 9 weeks, at room temperature for up to 7 weeks and at 37 degrees C for up to 4 weeks. The Fu types were still detectable at semen dilutions of up to 1:4. This polymorphism would provide a useful genetic marker for the medicolegal grouping of seminal stains.     

Application of an immunological method to detect trace amounts of dried human semen

An immunological assay based on a monoclonal antibody was used for identification of trace amounts of dried human semen in forensic science evidence. The monoclonal antibody (Mab 4E6) produced recognizes a human sperm-coating antigen which is specific to human seminal plasma. This antigen seems to be a protein secreted by the epithelial cells of the ejaculatory duct, which is stable indefinitely at room temperature. Mab 4E6 reacts positively with semen samples from individuals independently to their ABO group or secretory status, but does not react with semen from bull, ram, boar, horse, rabbit and dog. In the assay system developed, Mab 4E6 can detect human seminal plasma at concentrations of 0.5 micrograms/ml total protein. A similar sensitivity is found when human semen stains are eluted from forensic science samples and tested by the same assay. This method shows a good correlation with the microscopic methods routinely used. The method described is very sensitive and reproducible, it is time saving and special laboratory equipment is not needed.     

Analytical Challenge in Postmortem Toxicology Applied to a Human Body Found into a Lake after Three Years Immersion

The body of a 30‐year‐old woman was found in Como lake at a depth of about 120 meters in her own car after 3 years of immersion. The aim of this study was to evaluate psychoactive drugs as well as alcohol biomarkers in biological matrices. The following analyses were initially performed: GC‐MS systematic toxicological analysis on biological fluids and tissues; GC‐MS analysis of drugs of abuse on pubic hair; direct ethanol metabolite determination in pubic hair by LC‐MS/MS. After 7 years, the samples, that had been stored at ?20°C, were re‐analyzed and submitted to an LC‐MS/MS targeted screening method, using multiple reaction monitoring mode. These analyses detected citalopram (150–3000 ng/mL), desmethylcitalopram (50–2300 ng/mL), clotiapine (20–65 ng/mL), and ethyl glucuronide (97 pg/mg). The methods showed an acceptable reproducibility, and the concentrations of citalopram and desmethylcitalopram calculated through the two analytical techniques did not significantly differ in biological fluids.     

Vomit identification by a pepsin assay using a fibrin blue-agarose gel plate.

Reported is a simple and reliable method for identifying the presence of gastric fluid in forensic samples by an assay that reveals the pepsin activity. These samples are usually vomit found at the scene of a crime, either in fresh form or as a dried stain on clothing. The pepsin within the sample is assayed for its proteolytic activity which is revealed in a fibrin blue-agarose gel plate, as a result of an enzymatic reactivity that takes the form of a concentric, blue, translucent ring around the tested sample. Apart from being able to determine the pepsin content of fresh or recent forensic samples, this method has also achieved positive reactions in aged gastric fluid stains that were kept at room temperature. No body fluids other than the gastric fluid and no proteolytic enzymes other than pepsin show a positive reaction with the use of this method. This method has an additional advantage, in that the enzymatic activity seen on the gel plate can be photographed and the gel plate, on drying, can also be preserved as evidence.     

长期饮酒对急性中毒大鼠死后体液内MDMA再分布的影响

目的研究长期饮酒对急性中毒大鼠体液中亚甲基二氧甲基苯丙胺(MDMA)死后再分布的影响。方法 SD雄性大鼠360只,随机均分为A、B、C、D 4组;A、B组以白酒,C、D组以双蒸水为饮用液体,4周后各组按150mg/kg MDMA剂量灌胃,处死后分置于25℃、4℃条件下;以VARIAN CP-3800气相色谱仪分别检测处死时血乙醇含量和0～10d内体液样品中MDMA浓度。结果 0～10d不同条件下,大鼠血液、玻璃体液及尿液中MDMA的PMR浓度变化趋势均为先升高、后降低;各时间点A、B组和C、D组大鼠各体液样本MDMA浓度较0h均有显著性差异(P<0.05),各时间点A与C组、B与D组之间体液样本MDMA浓度有显著性差异(P<0.05);A与B组、C与D组之间体液样本MDMA浓度有显著性差异(P<0.05)。结论长期饮用乙醇会降低MDMA在体液样品中的再分布,其影响程度高低依次为血液、尿液及玻璃体液;低温也可减少体液中MDMA的再分布。     

用斑点ELISA方法检测p30确证人类精斑

作者建立了检测精浆特异性抗原p30的斑点ELISA试验方法,确证人类精斑。p30最小检出量为0.4ng。用该法盲测了室温存放1年的生物性斑痕180例,无一例假阳性和假阴性,证明用此法确证人类精斑的敏感性和特异性均优于传统的方法,具有操作简便、快速,检材用量小,结果准确等优点。     

一种改良酸性磷酸酶试验鉴定精斑的方法

本文报道了一种改良的酸性磷酸酶试验方法。用该法鉴定精斑，可克服非特异性反应，排除其它体液和植物汁液的影响。     

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.     

Alpha-amylase kinetic test in bodily single and mixed stains

Recently, in Italy, a murder and a putative sexual violence was accomplished on a child. A bodily fluids mixture on the child's underwear between the victim (female) and the suspect (male) was ascertained by short tandem repeat (STR) DNA typing and, due to the absence of seminal fluid, saliva from the suspect and urine from the child was hypothesized. In order to investigate the possibility of specifically and rapidly detecting saliva stains both alone and mixed with other bodily fluids, we used a quantitative spectrophotometric technique, named Amylase test, for the detection of alpha-amylases. We determined alpha-amylase activity and reaction kinetic curves in several samples collected from the child's underwear. In order to confirm our intuition, we first tested saliva, perspiration, and urine, singularly and in mixtures; second, several forensic stains including saliva, perspiration, urine stains, saliva/perspiration, and saliva/urine mixture stains were tested. Evaluating alpha-amylase activity values and time-course curves' behavior of alpha-amylase reactions we were able to recognize successfully, in all cases, the presence of saliva and to distinguish it specifically from other bodily fluids containing alpha-amylase. A further confirmation of our result was provided by STR DNA typing on several areas of the underwear: a clear correlation between alpha-amylases activity and male DNA was detected on all the samples evaluated.     

Spectrofluorimetric and Spectrophotometric Analysis of Two Analgesic Drugs in Pharmaceutical Formulations and Biological Fluids

Simple, reliable, sensitive, and accurate spectrofluorimetric and spectrophotometric methods were proposed for the determination of two selected analgesic drugs, namely tramadol and morphine, in pharmaceuticals and biological fluids. The proposed methods were based on the oxidation of the studied drugs by Cerium (Ce)IV in an acidic medium. The spectrofluorimetric method is based on measuring the relative fluorescence intensity of Ce(III) arising from Ce(IV) at 350 nm with an excitation wavelength at 250 nm. The spectrophotometric method involves on addition of a known excess of Ce(IV) to the studied drugs in an acid medium, followed by the determination of residual Ce(IV) by reacting with a fixed amount of methyl orange and measuring the absorbance at 510 nm. Different variables affecting the reaction conditions, such as the concentrations of Ce(IV), type and concentration of the acid medium, reaction time, temperature, and the diluting solvents, were carefully studied and optimized.     

Immunologic characterization of human seminal leucine aminopeptidase (LAP) and its medicolegal use

A new method for identification of seminal stains is described, based on the immunologic demonstration of leucine aminopeptidase (LAP), which is extremely abundant in human semen and specific for the prostate as well as semen. An antiserum against human seminal plasma was obtained by repeated immunization of rabbits with seminal plasma and Freund's adjuvant. Ouchterlony's double immunodiffusion test and Culliford's precipitin electrophoresis were performed to demonstrate specific proteins of seminal plasma. LAP activity was visualized with L-leucyl-beta-naphthylamide as substrate and with Fast Garnet GBC as coupler. The immunologic analysis of LAP produced two precipitin lines with enzyme activity. One was observed in kidney, jejunum, pancreas, prostate, as well as in semen, and was completely absorbed with kidney homogenates. The other was found only in semen and the prostate and was not absorbed with kidney homogenates. When the anti-seminal plasma serum absorbed with the kidney was used, the semen-specific LAP could be demonstrated by precipitin electrophoresis only in seminal stains stored for up to 2 months, whereas it was not demonstrated in stains from other human body fluids. By means of precipitin electrophoresis the detection of the semen-specific LAP was possible at semen dilutions of up to 1:32. The method described here greatly enhances the value of semen identification and is quite recommendable for the examination of stains in medico-legal practice.     

The effect of chilling, freezing, and rewarming on the postmortem chemistry of vitreous humor

The effect of chilling at the time of death on the postmortem chemistry of the vitreous humor was studied by using sheep heads obtained immediately following decapitation. One group of heads was kept at room temperature, while the remainder were chilled on ice or in ice water, then refrigerated or frozen. Vitreous humor specimens were taken at intervals over a 48-h period. Chilling inhibited the fall in the glucose concentration and the total carbon dioxide content and lessened the increase in lactic acid, compared to the room temperature group. Rapid glycolysis resumed when the heads rewarmed to room temperature starting at 6-h postmortem, but did not resume at later points. The rate of rise of the potassium and magnesium concentrations was also diminished in the chilled eyes. Freezing and thawing caused an abrupt increase in the potassium and magnesium levels, but other solutes were unaffected.     

Detection of methamphetamine in mouse femurs exposed to high temperature

Bone samples are valuable for examining the cause of death and circumstance leading up to death when body fluids are not available for forensic toxicological analysis. Examined were heat-induced changes in methamphetamine and amphetamine concentrations in femurs removed from methamphetamine-injected mice to determine if the burned bones could be used for toxicology testing. The femurs were heated at 100°C, 300°C, or 500°C for 10 or 30 min. The tissue structure of the heated femurs was preserved at 100°C for 30 min but was destructed at higher temperatures. Methamphetamine and amphetamine were detected in femurs heated at 100°C for 10 min, 100°C for 30 min, and 300°C for 10 min (with methamphetamine and amphetamine concentrations ranging from 0.36 to 35 μg/g and 0.54 to 47 μg/g, respectively). Methamphetamine and amphetamine were detectable when heated above their decomposition temperature as a result of limited heat transfer do to protection provide by the femoral muscle. Thus, the bone could be a useful analytical sample in cases of burn-related deaths, where it is difficult to collect body fluids.     

Amylase levels in semen and saliva stains

Amylase levels were determined for 148 semen samples and 20 saliva samples as well as for their corresponding stains. The effect of aging on the detectability of amylase activity in these stains was also investigated. The Phadebas amylase test was used for the quantitative assay of amylase. High levels of amylase in fluid saliva resulted in high levels being detected in saliva stains. Lower levels present in most seminal fluids produce little or no detectable amounts of amylase in stains. Interpretations are made as to the possible sources of amylase activity found in stains from laboratory casework based on both the amylase concentration and the elapsed time between collection and analysis. The evidential value of the presence or absence of amylase activity in casework stains is also discussed.