Describe how the Meselsohn- Stahl experiment was set up. Describe how the results of the Meselsohn- Stahl experiment provide evidence for semi- conservative replication

Describe how the Meselsohn- Stahl experiment was set up. • Culture E. Coli for several generations with amino acids containing 15N. Incorporate 15N into DNA • 15N bacteria washed and transferred into medium containing normal amino acids (14N); divide once more • DNA from both types extracted and centrifuged Describe how the results of the Meselsohn- Stahl experiment provide evidence for semi- conservative replication • Bacteria grown in 15N shows 1 band low in tube • Bacteria grown in 14N shows 1 band in upper tube • 2nd gen 15N shows 2 bands, 1 high one low • Implies 1 strand used as template for other as 2nd gen bacteria exhibit both bands