Meselson-Stahl Experiments

1. grow E. coli on medium containing N15

2. transfer bacteria to medium containing N14

3. after each generation of growth on N14 isolate DNA and run on cesium chloride gradient in ultracentrifuge

4. observe location of band of DNA

Important items

use of different isotopes of nitrogen 15N heavy; 14N light

use of Cesium Chloride to establish range of densities

use of ultacentrifuge to separate different densities of DNA

record DNA location on film; 2600A

 

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