Nirenberg and Leder experiment acid. Oswald Avery discovered that the substance responsible for producing inheritable change in the disease-causing bacteria was neither a protein nor a lipid, rather deoxyribonucleic acid (DNA). He and his colleagues Colin MacLeod and Maclyn McCarty suggested that DNA was responsible for transferring genetic information. Later, Erwin Chargaff discovered that the makeup of DNA differs from one species to another. These experiments helped pave the way for the discovery of the structure of DNA. In 1953, with the help of Maurice Wilkins and Rosalind Franklin’s X-ray crystallography, James Watson and Francis Crick proposed DNA is structured as a double helix.
Rosalind Franklin analysis was often ignored because of perceived feminist overtones in her book. Watson and Crick did not cite the X-ray diffraction work of Wilkins and Franklin in their original paper, though they admit having "been stimulated by a knowledge of the general nature of the unpublished experimental results and ideas of Dr. M. H. F. Wilkins, Dr. R. E. Franklin and their co-workers at King's College London". In fact, Watson and Crick cited no experimental data at all in support of their model. Franklin and Gosling's publication of the DNA X-ray image, in the same issue of "Nature", served as