Genetic Testing

genetic-testing-remadeEvery person’s genome is more than 99% identical to every other person, anywhere in the world. The differences that account for less than 1% of our genome are due to naturally occurring genetic variants. The most common sites of variation or changes in the genome are called single nucleotide polymorphisms, or SNPs (pronounced: snips).

We look for SNPs through a process called genotyping. Genotyping is the method of determining what genetic variants each individual has or doesn’t have.

What Does Genotyping Involve?

First, your DNA is isolated from your saliva sample and then copied several times. Once a large quantity of your DNA has been copied, it is cut up into millions of short pieces. The millions of short DNA pieces are then stained with a fluorescent chemical.

The short, stained DNA pieces are loaded into the GeneChip®. Each GeneChip® has more than 1 million pieces of synthetic DNA. The GeneChip® is placed in a rotating incubator (similar to a rotisserie-style oven) for 16 to 18 hours. The heat from the incubator helps the short, stained DNA pieces attach to the template DNA pieces inside the GeneChip®, like two sides of a zipper coming together. After heating, a second fluorescent stain is added. The second fluorescent stain creates a picture in which different colors identify spots in the participant's genome where there is a genetic variant (a difference from the synthetic DNA).

A laser is used to read the picture and a computer translates this information into a participant’s personal SNP profile.