Author Archives: ptcmichelle
I have hair for one of the people I want tested. I notice on TV that they use this all of the time. Can I use this? How about baby teeth? Would these stand up in court?
Unfortunately, hair often isn’t as good of a sample as television makes it look. On TV, you often see a crime investigator discover a single hair, and within moments they not only have a full DNA profile, but they know exactly who it came from. The truth is that technology simply isn’t there yet, though it could be someday.
In order for us to use hair, we need the hair roots. This is because there simply isn’t adequate DNA in the hair shaft. For us to have enough DNA to attempt the type of profile we need for a paternity test, we would need at least 12 hairs with the root bulb. This means that pulled hair is what we need. Typically, hair off of a hair brush is broken hair that doesn’t contain the root.
We often get asked about teeth or baby teeth as well. The main source of DNA in a tooth is the pulp, and the pulp usually doesn’t survive longer than one year after it has been extracted from the mouth. If there are bits of dried blood still on the tooth, we can attempt a profile from the blood but there is still no guarantee we will yield a profile.
Often times, when people are interested in using hair or baby teeth, it is because they do not want that testing party to know about the test. If secrecy is what you are after, there are other types of samples you can use that would give us a better chance of yielding a profile. Some examples of samples where we generally have a good chance at yielding a profile include: Toothbrush, Q-tips used on ears, electric razor clippings (for the skin cells in them), chewing gum, cigarette butts, soda straws, Kleenex or a clothing item with blood on it.
Other options you have, but don’t have as good of a chance at yielding a profile may include: Licked envelopes or stamps, the rim of glasses or bottles, tissue slides, fingernail or toenail clippings, and dried umbilical cords.
Any time you use a non standard sample (any sample that is not a buccal swab, tube of blood, or blood stain card) there is a fee for us to attempt a profile. This fee varies on the type of sample being sent, but generally ranges between $200 (most of the aforementioned options are $200) and $1200 (bone or teeth). In the event a profile is unsuccessful, the fee is non-refundable. Maintaining the chosen sample in a cool, dry area will maximize our chance of getting a profile. Keeping the sample in a paper envelope is better than keeping it in a zip lock bag.
It is important that only the intended person have used the artifact in question and no one else. It is also important that when handling the sample, you do not touch the part that needs to be tested. This is because if the sample yields a mixed profile (we discover more than one person’s DNA profile), the sample may not be used.
One last thing to keep in mind is that any time a sample is not collected with a legal chain of custody, that sample cannot be used for court or any other official purpose (social security, birth certificate, custody, child support, etc.) When a sample is collected with a legal chain of custody, the testing parties to a location where photo identification is checked, a photo is taken, and the collection is conducted at that time by a non-biased third party. Since hair, toothbrushes, and similar samples are typically just items taken from around the home, there is no way for us to verify the identity of the person that the sample came from, and therefore that test cannot stand up in court or be used for any official purposes. However, if you are simply trying to get a personal question answered, pursuing this route may still be worth it for you.