DNA Testing Facts

By John Landers

DNA testing, or genetic profiling, involves the analysis of an individual's skin, saliva, semen, blood, hair or other bodily material to learn about their genetic traits. Analyst examines the proteins, "chemical fingerprints" (metabolites) and chromosomes, which is the DNA. The purpose is to identify and study families and population groups. DNA testing is typically associated with criminal cases and is a part of the criminal appeals process. However, it is also used in a wide variety of other testing settings, including medical, forensics, paternity and genealogy.


Human beings inherit the DNA of their parents. Every person has 23 pairs of genes, one each from the mother and father for a total of 46 genes. Researchers and geneticists believe the human genome is somewhere around 20,000 to 25,000 genes. Genetic profiling examines the hereditary pattern that separates nearly every human being. DNA testing has been around since 1985, and in 1987 a Florida rapist was the first criminal convicted by the use of DNA evidence. Most DNA tests are touted as more than 99 percent accurate. DNA evidence can be lifted from samples that are many years old.


Besides genetic profiling, many DNA tests are used to not only isolate the presence of a disease, but also individuals' hereditary susceptibility to specific diseases and birth defects. This is done with the use of biochemical tests, which goes beyond the conventional DNA profiling and examines protein, RNA and a host of other elements. It also looks for aberrant genes that could lead to health issues.


Forensic testing is used to identify specific patterns in evidence discovered at crime scenes. Analysts evaluate 13 DNA regions. These properties are also called "loci" or "markers," which are the genetic fingerprints of an individual's DNA profile. Early DNA analyses were conducted with a procedure called Restriction Fragment Length Polymorphism (RFLP). RFLP's reputation for errors caused it to be abandoned as a DNA testing method. Today, Polymerase Chain Reaction (PCR) and Short Tandem Repeat (STR) are the most prevalent forms of DNA testing.

Other Uses

In paternity DNA testing, it can identify the father of a child with 99.99 percent certainty or with 100 a percent accuracy that a particular male is not the father. Many people take a simple cheek-swab test to learn more about their genealogy. These types of test are not conducive for determining the likelihood of contracting a hereditary condition.


Make sure the laboratory is accredited, such as the American Association of Blood Banks (AABB). AABB-accredited laboratories are required to meet or exceed certain conditions and follow stringent rules that will be accepted in nearly any court. The laboratory should consistently provide a 99.99 percent probability of inclusion. DNA testing is a two-part process: properly performing the test and correctly interpreting the test results.

About the Author

John Landers has a bachelor's degree in business administration. He worked several years as a senior manager in the housing industry before pursuing his passion to become a writer. He has researched and written articles on a wide variety of interesting subjects for an array of clients. He loves penning pieces on subjects related to business, health, law and technology.