Fredrick Douglas

-Was working on a project in 1928 that formed the basis that DNA was the molecule of inheritance. Griffith's experiment involved mice and two types of pneumonia. One was virulent and the other non-virulent. He injected the virulent pneumonia into a mouse and the mouse died. Next he injected the non-virulent pneumonia into a mouse and the mouse survived.

After this, he heated up the virulent disease to kill it and then injected it into a mouse. This time the animal survived as predicted. Last he injected non-virulent pneumonia and virulent pneumonia that had been heated and killed, into a mouse. This time the mouse died.

Griffith speculated that the killed virulent bacteria had passed on a characteristic to the non-virulent one to make it virulent. He believed this characteristic was in the inheritance molecule. This passing on of the inheritance molecule was what he called transformation.