Along with Vinograd, the experimenters had the year before perfected a way of using cesium chloride to establish a density gradient during centrifugation.
Edward Simon showed that the results of this experiment held in HeLa cells. When reviewing the manuscript that ultimately published this experiment's results, John Cairns suggested a reason why its results with salmon sperm were different. Along with Vinograd, the experimenters had the year before perfected a way of using cesium chloride to establish a density gradient during centrifugation. This pulse-chase experiment disproved Max Delbrück's ideas about the "unwinding problem." It grew E. coli in nitrogen-15 labeled media for several generations, then moved it to a nitrogen-14 medium and looked at the density of DNA in further generations. For 10 points, what doubly-eponymous experiment confirmed the semiconservative nature of DNA replication?
Edward Simon showed that the results of this experiment held in HeLa cells.
Meselson-Stahl experiment