Question

Explain Avery, McCarty, and MacLeod’s experiment in detail.

Answer 1

1. Avery, Macleod, and McCarty (1944) purified DNA, RNA, proteins (enzymes), and other materials from heat-killed S-type and mixed them with R-type to see which ones could transform living R-types to S-types.
2. Only those mixed with DNA were transformed into S-type bacteria.
3. They also discovered that protein-digesting enzymes (proteases) and RNA-digesting enzymes (RNases) did not affect transformation. This indicated the transforming substance was neither a protein nor RNA.
4. DNA digested with DNase inhibited transformation, suggesting that DNA caused the transformation.