How recent are accurate paternity tests?



And how did they do paternity tests before DNA testing? Before that, was there simply no way to prove who the father was?

In: Biology


The modern highly-accurate paternity testing using DNA came about in the 1980’s. The exact methods have changed and gotten faster and easier since then, but the accuracy has been the same (roughly 99.99%). DNA testing is the only method that can conclusively *prove* paternity; all older methods work by excluding who *couldn*’t be the father, and were less accurate.

Prior to DNA testing, there was something called HLA testing, which was invented in the 70’s. HLA is short for human leukocyte antigen, which is found on the surface of white blood cells. HLA testing would try to match the HLA protein in the parent and father. This method was roughly 80%-90% accurate, and could usually determine whether a biological relationship existed, but not necessarily the nature of the relationship (for example, it probably couldn’t tell the difference between a grandfather and a father)

Before HLA testing, the only method was through blood typing and serological testing which were discovered in the 1920’s and 1930’s. These were only about 30%-40% accurate at best, meaning if you had 10 potential fathers, you might only be able to eliminate 3 or 4 of them (sometimes even fewer, or none), leaving 6 possibilities with no further method of narrowing it down.