Forensic: Detection of Semen Stains

Crime laboratory personnel often face the difficult task to locate semen traces from sexual assault evidence within a short period of time. If UV light and alternate light sources are widely used within crime laboratories, scientific literature agrees that ALS shows many disadvantages. The main weakness being lots of false positive traces that are then time and money consuming to exclude from the analysis. Even more concerning, according to fabric and color, it is sometimes estimated that 30% of semen stains are missed by alternate light sources available on the market.

Acid Phosphatase tests, if more sensitive and specific, show many disadvantages. AP tests use toxic (carcinogen) “lab-prepared” reagents which are thus long and dangerous to use. Moreover, as reagents damage DNA, it requires to be done indirectly, which may then lead to mis-repositioning on evidence.

STK Sperm Tracker solves it all!

After years of research in collaboration with the French Nationale Scientific Police and ICBMS (UMR5246), AXO Science is now bringing to the forensic experts STK Sperm Tracker that improves both sensitivity and specificity of semen detection.



STK Sperm Tracker is based on an innovative technology and offers many advantages to crime laboratory experts in detecting semen stains:

Sensitive: do not miss any single semen stain by using the most sensitive technique available, whatever the color or fabric of the item

Specific: do not waste time and money with false positive, only semen will show, even if mixed with other body fluids

Non Toxic: human and environmental friendly. Get rid of carcinogen, time-consuming AP reagents

Easy and Ready to use: simple and rapid 4 steps protocol (spray water on STK, cover the item, press 3′, read result)

ISO 18385: forensic grade certified

-> VIDEO: STK Sperm Tracker is being used in routine by the French National Institute of Scientific Police (INPS):


When first tested they concluded:

tested in parallel with Crimescope (CSS filter and orange and red glasses) STK Sperm Tracker clearly showed its ability to overcome fabric constraints (improved sensitivity) and to carry out two operations in one: both pinpoint stains and reveal their acid phosphatase activity.

More reliable, faster and easier to set than the method currently in force within the INPS, STK Sperm Tracker represents a real step forward in the forensic field.

Emilie B. & Céline P. – Forensic Identification Specialists, INPS – LPS69

Download STK Sperm Tracker brochure

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Scientifc Article “Evaluation of the Sperm Tracker for Semen Stains Localizations on Fabrics” by the National Institue of Scientific Police (INPS/LPS69) and the University of Lyon


STK Sperm Tracker is available in different formats:

– Roll: 0,92m width x 40m long

– Roll: 0,92m width x 10m long

– A3 sheets: 20 pieces

For a quotation please contact