Chapter 11, Problem 6TY

Meselson and Stahl were able to demonstrate semiconservative replication in E. coli by

1. a. using radioactive isotopes of phosphorus to label the original strand and visually determining the relationship of original and new DNA strands.
2. b. using different enzymes to eliminate old strands from DNA.
3. c. using isotopes of nitrogen to label the DNA and determining the relationship of original and new DNA strands by density differences of the new DNA molecules.
4. d. labeling viral DNA before it was incorporated into a bacterial cell and visually determining the location of the DNA after centrifugation.