Technology

DNA testing technology is based on three simple facts, which we use to answer various questions about identity, paternity, and family relationships:

• All the cells of the body have the same DNA, also known as the genetic material.

This fact makes collecting samples for DNA testing simple. Unlike older methods for determining paternity, we do not have to use blood. We routinely use a buccal/mouth swab (a cotton swab rubbed against a patient’s inner cheek) to collect DNA.

• Each person’s DNA is unique.*

DNA from a buccal swab sample is used to create a DNA profile—a “snapshot” of a person’s genetic makeup. Because no two persons* will have the same DNA profile, the profile is often called a genetic fingerprint.

*Except for identical twins.

• Each person’s DNA is a combination of DNA inherited from the biological father and mother.

We can thus compare DNA profiles of different individuals to determine if there is a biological relationship among them. Those with similar DNA profiles will likely be related. A child’s DNA profile will have features from both parents’ DNA profile. Siblings will share some features in their DNA profiles. 

Learn about the DNA testing process in detail.