What can your spit tell you about your DNA?

From Spit to SNP: The Basic Process

­Unlik­e at-home pregnancy testing, which delivers results to the user as she watches, at-home genetic testing isn't so simple or home-based. You do get to provide the sample at home, but everything else requires the help of off-site trained scientists. You can't simply spit in a cup, dip in a wand and read the results. This is how it works:

  1. Visit the Web site of your preferred service provider. Three popular services are 23andMe, Navigenics and deCODEme. Next, open an account and order a test. Prices can range from $100 to $2,500, depending on the package you select.
  2. After your order is processed, the company mails a kit to you that includes any necessary equipment.
  3. Now comes the fun part. Using the supplied cup or tube, start collecting your spit. About 30 milliliters (2 tablespoons) of saliva are required to get a sufficient number of cheek cells. The deCODEme service actually uses a buccal DNA collector, which is a stick with rough paper on one end. You rub the paper on the inside of your cheek to collect the cells.
  4. Seal up your sample and place it in the conveniently provided preaddressed envelope.
  5. Mail it and wait patiently.
  6. The lab extracts DNA from your cheek cells and conducts SNP testing to see if you have any markers for certain diseases or disorders.
  7. When your results are ready, usually in about eight to 10 weeks, they're uploaded to your account and you're alerted by e-mail that the data is ready to be reviewed.
  8. What happens next depends on the service provider. Navigenics makes genetic counselors available to help you understand and interpret the data. Social networking is a major goal of the 23andMe service. You can use the company's site to network with other individuals who might share similar backgrounds or proclivities, like wet earwax. Seriously.

­All of the service providers offer security measures to protect your data and allow you to choose how much data is made available to you.