Fingernails, bodily fluids like blood, mucus, or semen captured on clothing, toothbrushes, condoms, and other items can be checked for viable DNA, and then compared to another individual's cheek swab to see if they are the same person or related. The extracted DNA can also be tested to see if it is from a male or a female. This test is typically ordered when someone wants to know if a DNA specimen left in their home or office belongs to themselves or another person. It can also be used to do a relationship DNA test, including paternity, in situations where the child or father isn't available or willing to provide a cheek swab.
Choose Alternative Specimen Type
We can attempt to extract DNA from a variety of alternative specimen types, including:
DNA test using teeth or fingernails
Fingernails are a good source of DNA and can be used if other specimen types (like cheek swabs or hair follicles) are not available. While DNA can also be extracted from teeth, this is much more difficult and should only be used in cases where other parts of the body are either not intact, too diseased, or otherwise unavailable for testing. Not all teeth or all fingernails contain viable DNA.
DNA Test using bodily fluids on fabric
DNA can be extracted from the fibers that are on a piece of clothing or fabric, especially if the fabric is soiled with bodily fluid like ejaculate or semen. This type of DNA testing can help determine whether someone was in a particular place at a particular time. If the DNA is determined to be viable, we can compare it to the cheek swab of another person to see if they are related or if they are the same person. We can also test it to see if it male or female.
Specimen Viability
Before we can use the DNA from a non-standard specimen like fingernails, teeth, or a piece of clothing, we need to do a viability study to ensure that there is enough DNA present. If there isn't enough viable DNA, you can resubmit another sample; however, keep in mind that there are no refunds, and therefore, submitting an alternative specimen carries some degree risk that you will not get an answer. The best practice is to always use the specimen that is the most likely to have DNA if it's available to you.