A large pop of E.coli grown in 15N growth medium for many generations
DNA extracted + centrifuged
Single heavy band low in tube (only 15N)
Bacteria transferred to 14N growth medium
AFTER 1 ROUND OF REPLICATION
DNA extracted + centrifuged
Single intermediate band middle of tube (15N + 14N)
AFTER 2ND ROUND OF REPLICATION
2 bands were seen
One intermediate band (15N + 14N)
One light band (14N + 14N)
Provides evidence for semi-conservative method of DNA
As each new DNA molecule has 1 original parent strand, and 1 newly synthesized strand
