History of genetics code for specific proteins, leading to the "one gene, one enzyme" hypothesis. Oswald Avery, Colin Munro MacLeod, and Maclyn McCarty showed in 1944 that DNA holds the gene's information. In 1952, Rosalind Franklin and Raymond Gosling produced a strikingly clear x-ray diffraction pattern indicating a helical form, and in 1953, James D. Watson and Francis Crick demonstrated the molecular structure of DNA. Together, these discoveries established the central dogma of molecular biology, which states that proteins are translated from RNA which is transcribed by DNA. This dogma has since been shown to have exceptions, such as reverse transcription in retroviruses.
X-ray crystallography polymethylcyanoacrylaon of Boin crystal parameters. Heating or burning of bones causes recognizeable changes in the bone mineral that can be detected using X-ray diffraction (XRD) techniques. During the first 15 minutes of heating at 500 °C or above, the bone crstals began to change. At higher temperatures, thickness and shape of crystals of bones appear stabilized, but when the samples were heated at lower temperature or for shorter period, XRD traces showed extreme changes in crystal parameters. X-ray diffraction has been demonstrated as a method for investigating the complex structure of integrated circuits. X-ray crystallography X-ray crystallography is a technique