Question

Answer the following question based on Meselson and Stahl's experiment on E. coli :

How did they distinguish the heavy DNA molecules from the light DNA molecules? Explain.

Answer 1

They distinguished the heavy DNA molecules from the light DNA molecules by centrifuging in CsCl density gradient. This method helps to separate DNA molecules into bands by spinning them at high speeds in the presence of another molecule, such as cesium chloride. It forms a density gradient from the top to the bottom of the spinning tube.