Product Description
Restricted sale – For forensic use only
This product is sold only to professional forensic and institutional customers, such as forensic and crime laboratories, law enforcement agencies, prosecutors’ offices and medical examiners, hospitals and sexual assault (SANE/SAFE) programs, and universities or accredited research and training institutions. It is not intended for personal or household use. Pro Lab Supply may verify the buyer’s institution and credentials before shipping and may cancel orders that do not meet these requirements.
What is STK Lab?
Mapping techniques often use toxic reagents that are time consuming and dangerous to use both for DNA and the operator. Alternate Light Sources are known for generating lots of false positives and also... false negatives.
As semen is most of the time deep in the fabric, STK Lab pre-impregnated paper is designed to find semen traces on any textile evidence.
STK Lab is ready to use, non-toxic, highly sensitive and specific to semen. It is the perfect solution to screen clothes, bed sheets and any kind of textile evidence.
Fully compatible with DNA extraction techniques, STK Lab is being used in routine in crime laboratories in the world for several years now and helped to solve thousands of rape cases.
STK Lab is a presumptive test for the detection of human male semen on absorbent evidence such as clothing, bed sheets, carpet or car seats. The impregnated paper reacts with the acid phosphatase found in human seminal fluid, and positive stains show a blue fluorescent signal under the STK UV Light (365 nm). It is a non-toxic alternative to traditional acid phosphatase (AP) tests that rely on lab-prepared toxic reagents, and to alternate light source (ALS) screening alone.
Key features
- Ready to use, non-toxic, highly sensitive and specific to semen.
- Wide rolls to screen large exhibits; easily cut to fit the evidence shape and avoid waste.
- Does NOT alter DNA; fully compatible with extraction techniques and DNA analysis.
- Available in two roll lengths: 33 x 3 ft (AXO-STK-9210) and 132 x 3 ft (AXO-STK-9240).
Specifications
| Catalog numbers | AXO-STK-9210: 1 roll, 0.92 m x 10 m (3 ft x 33 ft) AXO-STK-9240: 1 roll, 0.92 m x 40 m (3 ft x 132 ft) |
|---|---|
| Shelf life | 12 months following production |
| Storage | Keep away from light and heat, at room temperature between +14°C (+57°F) and +30°C (+86°F). Use within 3 months after opening |
| Material | Paper with a laminated reading side and a blotter side impregnated with reagents (analysis side) |
| Press time | 3 to 10 minutes, depending on fabric thickness |
| Reading | STK UV Light (365 nm), about 50 cm (~20 in) above the reading side. Positive result: blue fluorescent signal |
| Wet paper | Use within 30 minutes once wet; single use |
| Standards | ISO 18385 forensic grade. Batch number, produced according to ISO 13485 standards |
| Intended use | Presumptive test for human male semen on absorbent evidence. For forensic use only |
How it works
- Cut a piece of STK Lab slightly larger than the evidence (the roll can be cut to fit the evidence shape).
- Using a sprayer, saturate the absorbing side of the STK Lab paper with demineralized water.
- Cover the evidence with the wet absorbing side against it, laminated reading side up. STK Lab can be pinned, or the item can be “sandwiched” to test both sides.
- Press for 3 to 10 minutes with a press device or an even weight (minimum 20 kg/m²) without moving the paper.
- In the dark, read with the UV light about 50 cm (~20 in) above the reading side: semen stains glow blue.
- Mark the stain and take the sample from the original fabric, not from the STK Lab paper, for DNA analysis.
Always run a positive control (STK Positive Control) with each analysis to validate the reagent and your UV light.
Storage
Keep away from light and heat. Store at room temperature between +14°C (+57°F) and +30°C (+86°F); if these values are exceeded, validate the product with a positive control. Use within 3 months after opening. Once wet, use the paper within 30 minutes; it cannot be reused.
Cautions
- Do not use STK Lab and STK Spray on the same evidence.
- On white, UV-reflective fabric, lift the STK Lab paper and read the signal on the absorbing side.
- Fabrics washed in a washing machine are unlikely to give a positive result.
