DNA Testing Starting time Genetics is one of the most exciting scientific fields of our day.
Researchers in many areas of science are finding ways of applying the tools of genetics, and in medicine it has opened doors to dramatic new possibilities for the prevention and treatment of many kinds of disease—from depression to diabetes and Alzheimer's. With the invention of DNA testing, genetics has also had a real impact in a very different field--criminal law.
DNA testing reveals the genes of each individual person. Since the early twentieth century, scientists have known that all human characteristics—from eye color to body height to certain diseases—are contained in a person's genes and are passed from parents to children. Genes work as a chemical instruction manual for each part and each function of the body. Their basic chemical element is called DNA, a copy of which can be found in every cell. The existence of genes and the chemical structure of DNA were understood by the mid-1900s, but scientists have only recently been able to identify a person from just a drop of blood or saliva or a single hair.