Another major breakthrough in biochemistry occurred in 1943. That
year, building on research involving infectious bacteria, an American physician
and medical researcher, Oswald Avery, found the key to the transference of
hereditary traits. Deoxyribonucleic acid, more commonly known as DNA, was
first isolated by Swiss blologist Friedrich Miescher during the latter decades
of the nineteenth century. By the twentieth century, the structural form of DNA
was already being studied. Avery, in his famous experiment in the 1940s,
transferred the traits of one type of bacteria to another type. He did this by
mixing dead cells of the first type with live cells of the second. His experiment
provided the first confimwation of the link between DNA and inherited
characteristics. A decade later, scientists James D. Watson and Francis
Crick gave the first accurate account of DNA structure. Then, in 1957, they
presented the process of genetic encoding in DNA. Their work demonstrated
that the specific information carried in DNA is responsible for the synthesis of
speclfic proteins. These proteins then carry out specific cellular functions to
complete the encoding process.