Science Common Sense

1608 - What is the process to confirm DNA as the genetic material?

To confirm DNA as the genetic material, scientists did three important experiments:

  1. Griffith's experiment (1928): Frederick Griffith found that when he mixed a dead, harmless type of bacteria with a live, harmless type, the live bacteria became deadly. He didn't know how it happened, but he knew something had been transferred from the dead bacteria to the live ones.

  2. Avery-MacLeod-McCarty experiment (1944): Three scientists (Avery, MacLeod, and McCCarty) tried to figure out what was transferred in Griffith's experiment. They took the dead, harmless bacteria and broke them down into their parts. They found that when they added the DNA from the dead bacteria to the live, harmless bacteria, the live bacteria became deadly, just like in Griffith's experiment.

  3. Hershey-Chase experiment (1952): Two scientists, Alfred Hershey and Martha Chase, did an experiment where they labeled the DNA and proteins of viruses with special markers. They found that when the viruses infected bacteria, the DNA from the viruses entered the bacteria, but the proteins didn't. This showed that the genetic material was the DNA, not the proteins.

These experiments together confirmed that DNA is the genetic material that carries information from one generation to the next.

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