Detection of four DNA genetic marker systems to differentiate individuals in mixed seminal stain of two individuals / 中国法医学杂志

Objective To investigate personal identification of mixed seminal stain of two individuals, we combined the detection of genotyping autosomal, Y and X STR and sequencing mtDNA hypervariable Ⅰ (HV Ⅰ ) region. Methods We analyzed autosomal, Y and X STR with commercial kit and separating and sequencing HVⅠfragments of mixed seminal stain from two males by SSCP electrophoresis. Results Four genetic markers of the high amount sample can be obtained when mixed ratio is more than 1:10. When the proportion of two samples is close, the suspect could be excluded or, to some extent, identified by comparing with our results. Conclusion The combined detection of four genetic marker systems can, to some degree, solve the personal identification from mixed seminal stain of two individuals.

Fundamental issues in forensic semen detection / Problemas fundamentales en la detección forense de semen

Sperm detection can be an important factor in confirming sexual assault in cases of rape. A large number of cases received in a forensic laboratory involve sexual offenses, making it necessary to examine exhibits for the presence of seminal stains. The objective of this paper is to provide an overview of the most important methods and tests used in the identification of spermatozoa or constituents ofseminal fluid during the investigation ofalleged sexual assault cases in forensic medical practice. Furthermore, this paper focusses on the basic knowledge that is necessary to the graduate students who wish to specialize in forensic sciences.

La detección de esperma puede ser un factor importante a la hora de confirmar un ataque sexual en los casos de violación. Un gran número de los casos recibidos en el laboratorio forense tienen relación con ofensas sexuales, lo cual hace necesario examinar muestras de presencia de manchas seminales. El objetivo de este trabajo es proporcionar una apreciación global de los métodos y pruebas más importantes usados en la identificación de espermatozoos o constituyentes del fluido seminal durante la investigación de supuestos casos de ataque sexual, en la práctica médica forense. Además, este trabajo presta atención al conocimiento básico necesario para los estudiantes graduados que desean especializarse en las ciencias forenses.

The comparison of seminal stains extracted from swabs collected by physicians of the out-patient department and the forensic medicine department at Siriraj Hospital.

The comparison of seminal stains extracted from swabs collected by physicians of the out-patient Department (OPD) and the Forensic Medicine Department at Siriraj Hospital has been carried out. 261 swab samples were collected from January 1, 1988 through December 31, 1992. The results showed that the swabs from vaginal rape case victims collected by physicians at OPD were not satisfactory. Physicians in OPD should use great care in the collection of specimens of vaginal discharges particularly in cases of rape where such a specimen is key evidence in criminal and civilian procedure of Thai Codes. Additionally, in the author’s opinion, the rape victims should be immediately referred to forensic physicians for closer examination and collection of evidence.