Zinc test as a new tool for identification of human seminal stains

An extremely simple qualitative method for identification of seminal stains based on high levels of zinc in human semen is described. It uses reaction of 1-(2-pyridylazo)-2-naphthol with zinc to develop a deep red color. The data are presented on the sensitivity, stability and specificity of the present method. We can recommend it for identification of human semen especially in old or denatured samples.     

The LAP test. A new method for identification of seminal stains by a qualitative color reaction of leucine aminopeptidase.

A new simple method for identification of seminal stains is described. It employs a qualitative color reaction based on histochemical technique for demonstration of leucine aminopeptidase (LAP), which is extremely abundant in human semen. The method herein reported (the LAP test) is quite suitable for medicolegal examination of seminal stains as a preliminary test.     

Electronic data processing latex immunoassay for the identification of human seminal stains

Electronic data processing (EDP) latex immunoassay using anti-human seminal acid phosphatase (anti-HSAP) immune serum was applied for the species and organ identification of human seminal stains. This test proved to be highly sensitive and specific.     

The ABH reactions of seminal stains

The ABO grouping results from approx. 1000 seminal stains have been collected and analysed. Most of the stains came from rape cases where the ABO and secretor status of both complainant and suspect were known. The results of the survey provided information concerning the usefulness of elution and inhibition as methods of body fluid grouping, the relative strengths of reaction of the A, B and H antigens in body fluids and the interpretation of the ABH reactions of body fluid stains.     

A new criminologic procedure: study of L-cystine-aminopeptidase activity for the detection of seminal stains

L-Cystine-aminopeptidase (CAP) enzyme cleaves L-cystine-di-beta-naphthylamide substrate to beta-naphthylamine. The final product of this process is a violet azostain. CAP enzyme determination was developed for criminological procedures. CAP shows almost 100 times greater activity in human semen than in other body fluids. Samples taken at different time intervals (1 week, 1-3-6 months, 1 year, and 5-10 years) were investigated; they were dried on cloth and filter paper and then stored at room temperature for various time periods. The enzyme was also shown to be specific in the comparative studies performed with other human secretions (nasal discharge, saliva, vaginal secretion, feces, urine, breast milk) and fruit juices (raspberry, strawberry, apple, pear, plum, tomato, etc.).     

The zinc test as an alternative for acid phosphatase spot tests in the primary identification of seminal traces

The value of the acid phosphatase spot test in the primary visualization and identification of seminal traces is hampered by the sensitiveness of the enzyme to biodegradation. An alternative spot test is proposed, based on the high concentration of the more stable zinc metal in seminal plasma. The proposed zinc spot test is simple and suitable for on site investigation. Although the sensitivity in fresh stains is lower than that of the acid phosphatase spot test, this is largely compensated by the lower sensitiveness to biodegradation. The specificity for semen is higher than that of the acid phosphatase spot test. In vaginal swabs it was nevertheless seen, that samples should be taken within 24 h after alleged sexual assault to give reliable results.     

Detection of amphetamine in bloodstains,semen, seminal stains,saliva, and saliva stains

Low nanogram quantities of amphetamine were detected in 100μl samples of dried bloodstains using radioimmunoassay. Saliva, saliva stains, semen, and seminal stains also contained measurable quantities of the drug.     

Effect of water immersion on seminal stains on cotton cloth

Reports on identification of seminal stains and spermatozoa on washed clothing are available. However, their detection on such clothing seems to depend on the washing material and the procedure adopted. It is reported here that prolonged immersion in water does not affect the detection of stains and spermatozoa.Results of experiments on water-immersed cotton clothing from 12 to 144 hours of water immersion are presented here. It is seen that intact human spermatozoa could be detected on such material even at 120 hours.     

Blind field test evaluation of Raman spectroscopy as a forensic tool

Analytical instrumentation for Raman spectroscopy has advanced rapidly in recent years to the point where commercial field-portable instruments are available. Raman analysis with portable instrumentation is a new capability that can provide emergency response teams with on-site evaluation of hazardous materials. Before Raman analysis is accepted and implemented in the field, realistic studies applied to unknown samples need to be performed to define the reliability of this technique. Studies described herein provide a rigorous blind field test that utilizes two instruments and two operators to analyze a matrix that consists of 58 unknown samples. Samples were searched against a custom hazardous materials reference library (Hazardous Material Response Unit (HMRU) Spectral Library Database). Experimental design included a number of intentionally difficult situations including binary solvent mixtures and a variety of compounds that yield medium-quality spectra that were not contained in the HMRU library. Results showed that over 97% of the samples were correctly identified with no occurrences of false positive identifications (compounds that were not in the library were never identified as library constituents). Statistical analysis indicated equivalent performance for both the operators and instruments. These results indicate a high level of performance that should extrapolate to actual field situations. Implementation of Raman techniques to emergency field situations should proceed with a corresponding level of confidence.     

The use of scanning electron microscopy in the examination of seminal stains

Samples of human seminal stains on fabrics, paper and wood were observed with a scanning electron microscope (S.E.M). It seems a reliable, rapid and simple technique for the routine examination of seminal stains.