EXPERIMENTS BY AVERY, MacLEOD AND McCARTY
● Prior to the work of `color{brown}"Oswald Avery"`, `color{brown}"Colin MacLeod"` and `color{brown}"Maclyn McCarty"` (1933-44), the genetic material was thought to be a `color{Violet}"protein"`.
● They worked to determine the `color{Violet}"biochemical nature"` of `color{Violet}"transforming principle"` in Griffith's experiment.
● They `color{Violet}"purified biochemicals"` (proteins, DNA, RNA, etc.) from the heat-killed S cells to see which ones could `color{Violet}"transform live R"` cells into `color{Violet}"S cells"`.
● They discovered that `color{Violet}"DNA alone"` from S bacteria caused R bacteria to become transformed.
● They also discovered that `color{Violet}"protein-digesting enzymes"` (`color{Violet}"proteases"`) and `color{Violet}"RNA-digesting enzymes"` (`color{Violet}"RNases"`) did not affect transformation, so the transforming substance was not a `color{Violet}"protein or RNA"`.
● `color{Violet}"Digestion with DNase"` did inhibit transformation, suggesting that the `color{Violet}"DNA caused"` the transformation.
● They concluded that `color{blue}"DNA is the hereditary material"`, but not all biologists were convinced.
● They worked to determine the `color{Violet}"biochemical nature"` of `color{Violet}"transforming principle"` in Griffith's experiment.
● They `color{Violet}"purified biochemicals"` (proteins, DNA, RNA, etc.) from the heat-killed S cells to see which ones could `color{Violet}"transform live R"` cells into `color{Violet}"S cells"`.
● They discovered that `color{Violet}"DNA alone"` from S bacteria caused R bacteria to become transformed.
● They also discovered that `color{Violet}"protein-digesting enzymes"` (`color{Violet}"proteases"`) and `color{Violet}"RNA-digesting enzymes"` (`color{Violet}"RNases"`) did not affect transformation, so the transforming substance was not a `color{Violet}"protein or RNA"`.
● `color{Violet}"Digestion with DNase"` did inhibit transformation, suggesting that the `color{Violet}"DNA caused"` the transformation.
● They concluded that `color{blue}"DNA is the hereditary material"`, but not all biologists were convinced.