Frederick Griffith experiment with two strains of bacteria by injecting them into mice in various combinations. He found that when you mix dead bacteria with live, it's possible for the live strain to acquire some of the traits of the dead one. Why was this important

Frederick Griffith experimented on the Mice with the streptococcus pneumoniae strains. The virulent strain was called S strain smooth strain as it has a smooth layer whereas the avirulent strain was called the R strain or rough strain.

When he injected the virulent strain of bacteria by heat killing them and live R bacteria, he found that the mice were killed.

This shows that the live or avirulent bacteria became virulent or transformed into virulent bacteria by acquiring the virulent trait of the S bacteria. This led to the formation of the transforming principle.