Avery, MacLeod, and McCarty’s use of in vitro transformation

Avery, MacLeod, and McCarty’s use of in vitro transformation to identify DNA as the most likely hereditary molecule. A purified extract from heat-killed SIII bacteria successfully transforms RII cells in the control experiment. Destruction of lipids and polysaccharides  , proteins  , or RNA does not affect transformation; however, destruction of DNA prevents transformationAvery, MacLeod, and McCarty’s use of in vitro transformation to identify DNA as the most likely hereditary molecule. A purified extract from heat-killed SIII bacteria successfully transforms RII cells in the control experiment. Destruction of lipids and polysaccharides  , proteins  , or RNA does not affect transformation; however, destruction of DNA prevents transformation

Extract from heat-killed Slll bacteria . . Protease Control Lipids and ’ . added, RNase added, DNase added, no 5233302?“ pogzacrcgagades proteins RNA destroyed DNA destroyed y y destroyed Type RII added a Type Rll added a Type RII added a Type RII added a Type RII added J l l l l l 50 K“) a No lip 35, J J® @ No changes polysaccharides NO protein J0 @ Live type SIII No bacteria bacteria recovered recovered Conclusion: Transformation is not Conclusion: No transformation disrupted by the removal of lipids, occurs DNA is the hereditary polysaccharides, proteins, or RNA; molecule required for therefore, none of these is the transformation. transformation factor.