The History of DNA and Paternity Testing

Home paternity testing has proven to be a remarkable tool when it comes to establishing relationships. The evolution of technology means that a DNA test can identify paternity and other relationships with nearly 100 percent certainty. Before the advent of DNA testing, scientists used a number of biological techniques.

Eye Color

During the 1800s, the visible physical features of a child were analyzed to determine paternity. Family relationships came into question if a child’s eye color differed from both parents. However, Gregor Mendel uncovered genetic inheritance in 1865, which proved that iris color was the result of many different factors that did not necessarily match one or both parents.

Blood Typing

It was not until the 1920s that scientists discovered the variations in blood type. The system became known as the ABO system. However, in addition to having type A, AB, B or O blood, blood has other characteristics that made paternity testing a mere 30 percent accurate.

Serological Testing

A decade later, researchers uncovered more clues concerning blood characteristics that included the Rh factor, the Duffy and Kell blood group systems. Nevertheless, the new discoveries only enhanced the ability to test paternity by 10 percent, which was still not conclusive.

HLA Testing

By the 1970s, scientists identified the human leukocyte antigen. The protein is present in every body cell with the exception of red blood cells. Equipped with this information, researchers were then able to combine the results of HLA tests with blood typing and serological studies to successfully identify paternity 90 percent of the time. And HLA testing was very expensive.

RFLP DNA Testing

Though DNA structures were discovered in 1953, restriction fragment length polymorphism tests were not created until the middle of the 1980s. Using RFLP technology, scientists were able to remove DNA from blood samples and create profiles from both potential parents and the child to determine a match. At that point, paternity testing became 99 to 100 percent accurate, and took many weeks to get results.

PCR Technique

By the 1990s, DNA tests began involving a method known as polymerase chain reaction. Using this technique, scientists amplified small quantities of DNA and made billions of copies. DNA could also be collected from other cells besides blood samples. Furthermore, PCR technology meant that DNA tests were easier, faster and less expensive. The technique led to the convenience of home paternity testing.

Today, a home paternity test is accomplished by obtaining cells from the inside of the mouth using a simple cotton swab and analysis completed by a certified paternity lab. DNA test kits can be ordered directly from labs. However, the now makes kits available at Walgreens locations.