Oct 24 2016

Evaluation of the SPERM TRACKER™ for Semen Stains Localization on Fabrics


Semen stains localization is an important challenge and a prerequisite to genetic identification during forensic investigations. Often performed using either nonspecific techniques such as CrimeScope or/and acid phosphatase specific methods such as naphtyl, these detection requirements were in need of a new technique and procedure: rapid, simple, specific and non-toxic.

We are here presenting the results of a comparative study between mini-CrimeScope and the newly launch product STK Sperm Tracker™. Evidence are given with regards to the specificity, sensitivity and ease of use of the new product. Genetic analysis were also performed right after localization and demonstrated the full compatibility of the method with the subsequent DNA analysis.



Submitted by: Christophe Marquette, Université Lyon



For sperm detection on evidences, the Laboratoire de Police Scientifique de Lyon (INPS/LPS69) was neither satisfied by forensic source lights (lack of sensitivity and specificity) nor by the naphtyl based solution they were using which was requiring to use dangerous products for human health, was time consuming and requiring lots of hands-on.

A new technique for the detection of semen stain directly on fabric has been presented and validated. The comparison of the performances of the present method with the classically used mini-CrimeScope technique demonstrates the superiority of the new technique, both at the specificity and sensibility level.

Indeed, no cross-reactivity of adverse effect was observed in the presence of various body fluids such as, saliva, blood, vaginal secretion, urine and faeces. Moreover, the technique was also shown to enable the precise detection of semen stains on fabrics of different origins and composition but also on large pieces of fabric presenting different thicknesses such as trousers. Finally, genetic analysis was demonstrated to be fully compatible with the semen detection technique, for semen sampling but also for blood and saliva sampling. No doubt then that this technique will be widely used in forensic laboratories in the near future.

The Laboratoire de Police Scientifique de Lyon (INPS/LPS69) decided to use STK Sperm Tracker in routine for all sperm detection they are required to perform on evidences.

At ISHI 27, AXO Science was presenting STK Sperm Tracker to attendees. Many face the same difficulties and were happy to find this new specific, sensitive, non-toxic and easy to use technic for sperm detection on evidences.

Key collaborators on this project include: Émilie Borges, Stéphanie Desrentes, Céline Popielarz of the Laboratoire de Police Scientifique de Lyon (INPS/LPS69) – Institut National de Police Scientifique and Agnès Degiuli and Loïc J. Blum of the Univ Lyon.