Visualization of Replicating Mammalian and T4 Bacteriophage DNA

Many of the problems associated with DNA replication are topological ones. It is not surprising, therefore, that the first visual studies of replicating DNA, the autoradiographic studies by Cairns (1963a, b), contributed so much to our present understanding of replication of the E. coli chromosome. Visual techniques have also been used to show that the major topological features of E. coli DNA replication are true, as well, for Mycoplasma DNA replication (Riggs, 1966; Bode and Morowitz, 1967).