Hair DNA Testing

14 Aug 2017

The standard for paternity testing and other DNA tests is the oral swab. This is because a swab is so simple to use and offers a high success rate. However, many people inquire about using other samples for testing. Hair DNA testing is in fact one of the most common tests people wish to have carried out but there is much to say about hair and the validity of using this sample in a test.

Hair DNA Testing: But what is hair?

Hair is divided into two parts- the shaft which is what you see above the surface of your skin and the root or follicle which is below the surface of the skin. Hairs are made up of a type of protein known as keratin and are made up of between two-three intertwined layers.

Detective and criminal investigation films are somewhat misleading especially when the police pick up the hair sample with a pair of tweezers for DNA analysis. Hair that is cut or shed does not unfortunately contain any nuclear DNA. For hair DNA testing to be successful the hairs must have the hair follicle attached. Most serious and responsible DNA testing companies will discourage strongly using a sample of cut or shed hair for paternity testing and most other tests.

Cut hair samples are no of course entirely useless- they in fact do just fine for a very specific type of test known as the MtDNA test. The MtDNA test (Mitochondrial DNA test) is used to determine whether two people share the same maternal line and given the low rate of mutation in the type of DNA, this test is rather accurate. However, this is the only type of hair DNA test you can have carried out unless you can specifically see a white ball attached to the end of the hair (this little ball would be the hair root).

If hairs have been ripped or torn from the scalp or plucked, then you can send these in for DNA testing. Hair DNA testing with freshly plucked hair is of course always better and a minimum of 5 hairs is recommended. If the hair is very old, one can opt to use advanced testing methods but these will come at an added, extra cost. Nevertheless, whether the hair is old or freshly plucked, you can still conduct your hair DNA paternity test.

How do I collect and send my hair DNA sample?

Once you have determined the type of test and whether the hairs you possess do or do not have the root, you can simply put these in a dry paper envelope making sure not to touch the hairs as much as possible and send these for laboratory analysis.

With hair DNA testing other than to carry out an MtDNA test, the success rate is 75%; thus, if the hairs contain the follicle, laboratories have a fairly high chance of extracting the necessary, undegraded DNA to conduct the type of test you have opted for. Always contact the company you choose for your test before sending any DNA samples.