The InSite Semen Detection Kit is on 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.
- 15 Acid phosphatase (AP) test strips in a sealed canister with a desiccant cap
- 10 Prostate specific antigen (PSA) test strips in sealed individual pouches
- 5-mL dropper
- Instruction sheet
- I did a PSA test, but the test line is just barely visible. Is this a positive test?
- I did an AP test which came out POSITIVE, but the subsequent PSA test was NEGATIVE. Is this a positive test?
- How long can semen in stains be detected?
According to the literature, there is a 90% probability this is a true positive test. However, this is just academic and from a practical point of view, the test result should be regarded as inconclusive. This calls for further investigation, perhaps with a different method of surveillance--for example, covert video. In order to be certain that the stain contains semen, the test line must be equal or greater in intensity to the control line. This represents a 100% probability that the stain in fact contains semen.
This test is presumptively positive for semen, but it doesn't prove it's semen, since the PSA test was negative. Therefore the test should be regarded as inconclusive. This test result sometimes happens in cases where there is only a trace of semen on the garment, and the AP test paper absorbs it all, leaving nothing for the PSA strip to detect. If you are suspicious that there is only a trace of semen there, then do the PSA test first. Using a Q-tip will allow an AP test to be performed after a PSA test. Keep in mind the AP test may be NEGATIVE even though the PSA test is strongly POSITIVE, because the PSA test is 1000x more sensitive than AP. PSA is the definitive test for semen, and the AP-PSA combination test is designed for strong semen stains, where both tests will be strongly positive.
For years, but the long answer is: acid phosphatase (AP) can be detected in semen which has been discharged up to 17 hours after intercourse, and prostate specific antigen (PSA) for up to 36 hours. Once semen has been discharged, then its chemical components become stable for years. The explanation for this is that both AP and PSA are proteins, and must have a certain three-dimensional configuration to work. The vagina presents a hostile chemical environment however, and rapidly denatures seminal proteins in a fashion similar to egg whites when they are cooked. After discharge, the residual non-denatured proteins are no longer exposed to a hostile environment, and there is virtually no time limit for their detection. PSA actually has been detected in semen stains over 30 years old. Items tested more closely to the time of suspected intercourse give a more strongly positive test.
- Additional Information
availability Usually ships the same business day