Semen Detection Kit

$99.95 $79.95

The Semen Detection Kit allows simple examination of up to 25 garments or surfaces for detection of rape or proof of sexual activity.

The Semen Detection Kit is one of the only semen detection kit with two types of tests: Acid Phosphatase (AP) and Prostate Specific Antigen(PSA).

Use both strips together to provide conclusive evidence of semen on just about any material or surface.

The Semen Detection Kit is easy to use and yields instant results with the AP test strips, or results after 10 minutes with the more sensitive PSA test. It is designed to detect traces of semen that has been discharged during sexual intercourse and up to 36 hours later.

It contains 15 AP test strips in a resealable pouch with desiccant, 10 PSA test strips in sealed individual pouches and a 5-mL dropper. The AP strips can detect semen down to a 1/2000 dilution, while the PSA strips can detect semen to a 1/500,000 dilution.
The kit is designed to be used by men who suspect their spouse or girlfrien may be engaged in sexual activity outside of their relationship. It also can be used by professional investigators, and parents concerned about whether their teenage daughters are sexually active or in cases of rape investigation.

Are they cheating?


Semen may be detected on undergarments up to 17 hours after intercourse with the AP test strips, and up to 36 hours after intercourse with the PSA test strips. The test kit includes both types. The AP test is presumptive, and a positive result should always be followed by a PSA test for confirmation of the presence of semen.


The PSA test is 100% specific for semen at a dilution of 1/500,000 or less. This means that the probability of a false positive result is essentially zero within the first 12 hours after intercourse. In order to be sure that the semen did not come from you, you must not have had intercourse with your spouse for at least three days prior to the test.

                    Is this a legitimate forensic test?

Both the PSA test and the AP test are used for the forensic detection of semen by professional investigators worldwide. The PSA test in particular has been validated for use in forensic investigations, and the small amount of PSA present in other bodily fluids has been shown not to interfere with the detection of semen.

How does this kit compare with other test kits on the market?

It has 25 test strips and is designed for long-term surveillance, since sometimes it takes awhile to catch adulteresses. Most other kits on the market have one or two test elements, and are designed for short-term use. In addition, this kit is unique in that it has two kinds of test strips: AP and PSA. In case of a strong stain, both tests will be strongly positive and will provide the investigator with a more certain conclusion that the item being tested does in fact contain semen. The AP strips are designed for quick field use, and only require the investigator to press the test paper against a moist stain, with results appearing in 15 sec. These strips also have a peel-off adhesive backing, and conveniently can be affixed to a notebook for permanent record-keeping. Finally, the PSA test procedure has been simplified so that the home user simply extracts the item to be tested in a coffee cup, and then inserts a test strip into the cup with no laboratory required.

Will the AP test strips leave stains?

There is a possibility the azo dyestuff in the AP test strip will stain a test garment. Therefore, if you are concerned about this, you should first wet the garment with a few drops of water, press a cotton-tipped swab against the wetted area and then press the swab against the AP strip. This method ensures your spouse will not be any wiser to the fact you are testing her garments.

Can this kit be used to test a man?

The kit will identify semen stains on garments and other fabrics, including men's underwear. However, there are many legitimate reasons why a man would have such stains on his undergarment--for example, nocturnal emissions. Therefore, we question whether any inference of infidelity can be drawn solely from the presence of semen stains on the undergarment of a man. Such evidence must be combined with other data, such as direct surveillance, in order to reach a meaningful conclusion.

Simple procedure

1. AP test: place 5-10 drops of water on a suspect area of the garment. Press an AP strip against it. A color change to bright purple within the first 60 seconds is a POSITIVE test. If the test is POSITIVE, proceed with a PSA test to confirm the presence of semen. If the test is NEGATIVE, but you are suspicious there might be a trace of semen on the garment, do the PSA test anyway.

2. PSA test. Place 15 mL of water in a coffee cup using the supplied dropper. Then, manually extract the suspect area (i.e. crotch) of the garment by repeatedly allowing water to soak in, then pressing it out. Finally, wring out the garment into the cup. Place a PSA test strip into the cup and wait 10 minutes. Then, take the test strip out and lay it on a clean dry surface. Read the test strip after 10 minutes. A POSITIVE test is indicated by two lines as shown below. A strongly positive test will be clearly visible within two minutes, while a weakly positive test may take the entire 20 minutes to become evident.

If you are testing absorptive pads (used during a woman's menstrual period), then place 25 mL of water into the coffee cup (for a full pad) or 10 mL for a mini-pad, and repeatedly extract the pad manually. Then, wring out the pad into the cup and discard it. Do the PSA test as usual.

  • 15 AP test strips in a resealable pouch with desiccant
  • 10 PSA test strips in individual sealed pouches
  • 5-mL dropper
  • Instruction sheet

Materials not supplied but required
  • Distilled or deionized water
  • Latex gloves
  • Disposable cup
Optional: UV Light for Stain Detection