Write a short note on the biochemical characterization of the Transforming Principle.

(N/A) Prior to the work of Oswald Avery,Colin MacLeod,and Maclyn McCarty ($1933$-$1944$),the genetic material was thought to be a protein.
They worked to determine the biochemical nature of the 'transforming principle' in Griffith's experiment.
They purified biochemicals (proteins,$DNA$,$RNA$,etc.) from the heat-killed $S$ cells to see which ones could transform live $R$ cells into $S$ cells.
They discovered that $DNA$ alone from $S$ bacteria caused $R$ bacteria to become transformed.
They also discovered that protein-digesting enzymes (proteases) and $RNA$-digesting enzymes $(RNases)$ did not affect transformation,so the transforming substance was not a protein or $RNA$.
Digestion with $DNase$ did inhibit transformation,suggesting that the $DNA$ caused the transformation.
They concluded that $DNA$ is the hereditary material,but not all biologists were convinced.