Proof that DNA was the source of genetic information

Text Box: Fig. 3 Crick and Watson examine their DNA model 1953 Text Box: fig. 2 Hershey and Chase's experiment backed the theory that DNA was the material cells use to carry genetic information Text Box: Fig. 1 X-ray crystallographic image of DNA. Franklin could not determine if there was 2 or 3 strands in the helix 1952  A.D. Hershey and Martha Chase
(fig. 2)used radioisotope tagging of the protein coat of a virus with 35SULPHUR and the DNA inside with 32PHOSPHOROUS.  After the virus replicated and killed the bacteria cells the P was found in the bacteria and S in solution above after centrifugant. Thus proving DNA was the source of genetic information.
 Structure of DNA
Rosalind Franklin (crystalographer)
X Ray diffraction (Fig. 1 ) revealed a helical pattern to the structure of DNA in 1953 the information was later used by Watson and Crick to determine the structure of DNA. They never mentioned her in their biography. 

Chargaff - (1951) noted "regularities" in the base composition of nucleic acids, which they considered "reflected the existence in all DNA preparations of certain structural principles" . He identified a species-invariant component of the base composition, > %A = %T and %C = %G.
This "first parity rule" was dramatically confirmed by the Watson-Crick double-helix model (Watson and Crick, 1953)
Crick and Watson fig. 3 - deduced the structure of DNA in 1953 using some  information from Chargaff and Franklin's works. They determined that DNA is a double helix made of ATCG nucleotides  2nm in width with a helical turn every 3.4 nm.
They won the Nobel prize for this work   in 1962.