SPERM HY-LITER™ for the identification of spermatozoa from sexual assault evidence

Abstract

Accurate microscopic identification of human spermatozoa is important in sexual assault cases. We have compared the results of examinations with (1) a fluorescent microscopy method, SPERM HY-LITER™, and (2) Baecchi's method for identification of human spermatozoa. In 35 artificial, forensic type samples, spermatozoa were identified in 45.7% with SPERM HY-LITER™ in Copenhagen, in 54.3% in the laboratory of the manufacturer of SPERM HY-LITER™, and 40.0% of the samples with Baecchi's staining method. When differences occurred between the two methods, it was significantly more often that SPERM HY-LITER™ detected spermatozoa when Baecchi's method did not (ts=6.567, df=1, P=0.048). This trend was also seen in selected compromised or degraded samples and in selected adjudicative samples. The reactions with spermatozoa from dog, horse, pig and bull were negative with SPERM HY-LITER™, whereas Baecchi's method was non-selective. Data from forensic casework samples in Copenhagen from two years (2008 and 2009) are presented. The samples from 2008 were investigated using Baecchi's method, while those from 2009 were investigated using SPERM HY-LITER™. The frequencies of positive results were similar between the two methods for the two years (27.9% and 32.1% respectively). Analysis of acid phosphatase (ACP) activity for the positive results obtained for these two years does not support the use of a negative ACP result as a prescreen for microscopic analysis for spermatozoa.

Postmortem identification of spermatozoa on human skin based on fluorescent monoclonal antibody method

“…The identification of human spermatozoa can be extremely difficult in challenging samples with low sperm count, high epithelial cell density, mixtures of cells and microorganisms, degradation of sperm cells with detachment of the tail from the head [9,11]. The stained HE skin in the present study reRyc.…”

“…Rape is usually an unwitnessed crime, thus the identification of spermatozoa has a great impact on the outcome especially after passing a period of time from the incident [4,7,9]. So, the presence of sper- [4,7,9].…”

“…So, the presence of sper- [4,7,9]. Należy zatem rozważyć okres przeżycia plemników w pochwie, na odzieży i na skórze ofiary [10].…”

“…Zależność między średnią liczbą plemników w 3 badanych grupach i czas upływający od depozycji nasienia. G1: grupa 1 -ujemna kontrola, G2: grupa 2 -pozytywne próbki wybarwione HE badane pod mikroskopem świetlnym; G3: grupa 3 -pozytywne próbki barwione Sperm Hy-Liter  badane pod mikroskopem fluorescencyjnym nabłonka, mieszanin komórek i mikroorganizmów, a także rozkładu plemników przebiegającego z oddzieleniem główek od witek [9,11]. W próbkach skóry wybarwionych HE wykorzystanych w niniejszym badaniu główki plemników oddzielone od witek stwierdzano już od punktu początkowego analizy.…”

“…Due to the intense fluorescence, as few as one spermatozoa can be identified among a dense sample of vaginal epithelial cells common in sexual assault type swabs [9]. It is simple to use, highly specific for human spermatozoa, sensitive, reliable, faster evaluation of slides, allow viewing of the slides at low magnification and allow detection of spermatozoa in old cases.…”