The method of DNA replication was confirmed by Meselson and Stahl using the following experiment:E. coli bacteria was grown on a medium containing 15N for many generations so the bacteria would incorporate the nitrogen into their amino acids and nucleic acids.The bacteria was transferred to a medium containing 14N for a single generation. The DNA was then extracted and centrifuged in a special solution of caesium chloride.Lighter molecules collect closer to the top of the centrifuge and heavier molecules sink lower.The results are illustrated below: