Oswald Avery was a physician and a medical researcher that continued Griffith's research, in 1932, after he died. He continued the research that DNA was genetic material. He exposed the rough cells to different molecules in a new experiment to see which one would cause it to transform into a smooth cell, and finally he reported that the transforming substance, or the genetic material of a cell, was DNA.

This discovery eventually led to the genetic code.

Oswald Avery