This test determines if a stain is semen or contains seminal fluids. The test will not provide a DNA profile of whose semen it is (see here for DNA Profiling). At PTC Laboratories, we use visual inspection as well as chemical analysis on the alleged semen stain(s). These are confirmatory tests that confirm the sample is semen and/or contains sperm.
This service is also available to law enforcement agencies who need reliable and conclusive testing of rape kits or other forensic evidence.
Cheaper, over-the-counter testing kits are available but they are often inaccurate. This is because most of them use presumptive tests that test for certain hormones present in semen, such as the Acid Phosphatase (AP) and Prostate Specific Antigen (PSA) tests. These tests do not confirm whether the stain is actually semen.
Samples submitted to PTC Laboratories could be a bed sheet, sofa cover, clothing, rape kits, or other forensic evidence. The stain should be at least 5 x 5 mm in size. However, these types of samples are known as Unusual Samples and will incur an unusual sample fee, as we must first extract the DNA in order to analyze it. You can view our Unusual Samples page to see what other types of samples can be used for this test. Contact us for more information.
On the other hand, if the stain is fresh, use sterile cotton tips to swab the stain. We also have DNA Sample Collection Kits for this use and can post a kit to you. Cotton swabs are considered standard samples and we do not charge an unusual fee if you submit this type of sample, however you must be very careful and precise in how you transfer the suspected semen onto the cotton swab.
Please contact us to have a confidential discussion about the suspected stain and the type of sample you wish to submit.
ONCE I KNOW IF THE STAIN CONTAINS SEMEN, I ALSO WANT TO KNOW WHO IT BELONGS TO. HOW DO I KNOW THIS?
Once you know whether the provided sample contains semen, you can decide to do a DNA Profile of the semen. This will generate a genetic profile of the donor of the semen. You then need someone to compare the semen's DNA profile to, and see if they match. To do this, you also need to do a DNA profile of the person/s you want to test the semen profile against.
For example, in criminal cases, a suspect will give a DNA sample, which will be used to create a DNA profile. This genetic profile is then compared against the DNA profile generated from the semen sample. Similarly in infidelity cases, a DNA sample from a spouse or partner will be used to generate a DNA Profile, and this would be compared against the DNA profile generated from the semen sample.
In the case of infidelity cases, it is advised to also send a DNA sample of your spouse or partner at the same time that you send the initial stain containing suspected semen. This will save you having to pay a second courier fee. Please see DNA Profiling for more information.
Please note that there is no chain-of-custody of the initial semen sample, this test (and therefore any DNA Profile comparisons) can only be used for peace-of-mind purposes.
Before purchasing this test, it is important to contact us first, to discuss your requirements and whether this is the right test for you.
WHAT IS INCLUDED IN THE TEST PRICE?
The price for this test includes:
- 24/7 personal customer support in English and Thai.
- One (1) shipment of your samples (up to 0.5 kg in one shipment), by first-class, international priority courier to our lab in the USA.
- Testing of DNA samples provided on cotton tip to determine whether it is semen or contains seminal fluids. To use unusual samples in this test (such as a stain on material/fabric), you will need to add this option to your order. Scroll down the page to add this option to your order.
- One (1) original, notarized English-language report, and one (1) original, notarized Thai-language report.
- Emailed results as soon as they are ready.
- Posting of hard-copy, notarized results to anywhere in the world by regular mail. To express the postage of your hard-copy results, you can upgrade to first-class, international priority courier. Scroll down the page to add this option to your order.