The final proof for DNA as the genetic material come from the experiments of
(2) Hershey and chase
(3) Avery, Macleod and McCarty
(4) Hargobind Khorana
(2) The final proof that DNA is the genetic material came from the experiments of Alfred Hershey and Martha Chase (1952). Griffith's experiment proved the existance of genetic material while Avery, MacLeod and Mcarty worked to determine the biochemical nature of transforming principle.
Concept Enhancer Hershey and Chase during their experiment, grew viruses in two mediums, one containing and other, when these were allowed to infect bacteria, they observed that viruses containing were radioactive while those with protein were not radioactive. Hence, DNA not protein coat entered bacterial cells from viruses.