Archiving your Family's DNA
by Kevin F. Duerinck, Esq.
Editor's note: Kevin Duerinck has a university degree in biology with a minor degree in chemistry. His training, which he received before the recent breakthrough in our knowledge about genetics, included courses in genetics, including an upper level course. By no means an expert in the field of DNA, he remains interested in the subject and is presently conducting a DNA research project in his family.
You wake up one morning and finally decide to do it. You have been thinking of saving your DNA, as well as that of your parents, for future DNA testing. Your ideas may be for genealogical purposes, such as finding whether people with the same or similar surname are related to you. Maybe you thought that if your DNA was in a database you might run into people who match your DNA even though they have different surnames and live half the way around the world. Maybe you thought that you might be a relative of Cheddar Man, a 9,000 year old man who lived in the area now known as Great Britain.
Maybe your idea was to save a family member's DNA for future medical DNA testing if a medical problem ever arose that might lend itself to resolution through genetics. Who knows? Medical cures unknown today could be cured in the future through gene therapy, the injection of a new, working gene. So you reason that in order to avail yourself of this technology, you better start collecting the DNA of all of your family and establish that Family DNA Library.
These are just two examples of why people want to collect and preserve the DNA of their family members. But how does one go about collecting that DNA and how is it stored? An article of this scope cannot solve all your problems. You have to be the one to do research by reading books and articles on the subject, visiting web sites, sending e-mails and calling companies that are involved in this area. As with all areas of life, it is buyer beware. Who knows if some of these methods will keep the DNA available for analysis in 10 to 25 years or more? Some of the methods used for collection, while cheap, may prove to add costs on to any future testing because of the difficulty of extracting the DNA by the company. Such is the case with collecting lockets of your loved one's hair. However, if you have hair of an ancestor and nothing else, as is the case sometimes, it may be worth the extra money to have their DNA tested. More about that later.
Types of DNA
For our purposes here, there are two types of DNA to be concerned with. The first is y-chromosome DNA (y-DNA) which is found in the nuclear DNA of the cells. Y-DNA testing follows the paternal line back in time. Males comparing like or same surnames generally send samples of cheek cells or blood to a testing lab and find out if they are related through a most recent common ancestor. The second DNA type is mitochondrial DNA (mtDNA) which is in the portion of the cell that does not contain nuclear DNA. MtDNA testing follows the maternal line back in time. However, you should also know that male and female offspring receive their mtDNA from their mother. That means that females as well as males can have their mtDNA tested in order to follow the ancestors of their mother, their mother's mother, and so on. As a result, a male can begin a mtDNA test project, and he will try to find other people who may match the mtDNA of his maternal line, hopefully ending up with a most recent common ancestor that matches another supposedly unrelated individual.
From a scientific viewpoint, the order of preference for testing DNA samples would be 1) blood, 2) buccal swab, 3) hair. I will talk a little about each type of sample in the following paragraphs.
While this is a preferred method, buccal swabs have come into their own subject to provisos set out below. Blood provides high quality and high quantity of DNA. The testing labs are able to run numerous tests for analysis on the same sample. It is a bit more invasive than the other sample types of cheek swabs and hair, requiring your blood to be drawn by a medical professional. This is the preferred method for DNA testing for medical conditions.
Buccal (cheek) swabs
Buccal swabs are being used more and more in identification and relationship testing. They provide sufficient quantity and quality of DNA. Their collection is a less invasive procedure than blood. People can scrape the inside of their cheeks within the privacy of their own homes and ship the samples to the lab. A caveat is that the DNA generally must be isolated or fixed within 30 days for best results. Many genealogical testing companies are starting to use this method.
You can have hair analyzed for y-DNA and mitochondrial mtDNA. For mtDNA analysis, you can just use the hair itself. However, for y-DNA you must get the "root" or "bulb" of the hair. The root contains the nuclear DNA which includes y-DNA. You will also see discussions about the "shaft." The shaft is the hair without the root or bulb, and thus without the nuclear y-DNA. Trying to retrieve the DNA from hair shafts is difficult and time consuming and could add costs to any tests.
Commercial DNA Preservation
You must look at why you want to store DNA. Is it for genealogical relationship testing purposes? Is it for DNA testing for genetic medical diseases? Is it for hopefully regenerating body parts in the future? For cloning? On the Internet there are many links to company sites that offer various methods of preserving your DNA. Some charge relatively few dollars for a swab to brush the inside of the cheek (buccal swab) and a card with chemicals to preserve the DNA.
Then you just store the card in a dry place. Some offer a range of services at all price levels. These include sites where you place your DNA on cards you store yourself or send to storage at the company's facility. Some of these storage companies will store a frozen blood sample for many years, at a cost of a few hundred dollars.
The web sites of these commercial companies are easy to find using your favorite search engine to look for phrases such as "DNA identification", "DNA storage", "DNA profiling", "DNA extraction", "DNA collection", "genetic testing". You will find information on disease risks, inheritance rights, genealogy, identification, and medical history.
Be aware that the pricing is not always evident from the information on the web site.
As always: caveat emptor.
© 2001 Kevin Duerinck