Alternative Modes DNA replication:
Semiconservative, Conservative, & Dispersive
The Meselsohn-Stahl experiment used density gradient centrigugation to follow the behavior of newly-synthesized DNA strands. The results are shown on the right, in a figure taken from the original 1958 paper.

Homework: The diagrams show the alternative "conservative" and "dispersive" models, and the actual results.
       (1) Explain how the data support the semi-conservative model.
       (2)   At which stage is it possible to eliminate the alternative Conservative and Dispersive models of replication? Explain.


Figure © 2004 by Griffiths et al. ; text © 2011 by Steven M. Carr