DNA Segregation in Escherichia coli : Observations by Means of Tritiated Thymidine Decay

Abstract
Escherichia coli, strain 15T-L-, inactivation by H3-thymidine decay was used in a study of DNA segregation. Two characteristics of the inactivation curves due to H3-thymidine decay, the initial slope and stable fraction, enable the mode of segregation to be defined. The results suggest that the segregation pattern is consistent with a semiconservative model of DNA replication. The data on the stable fraction indicate that the DNA of strain 15T-L-, under our experimental conditions, may be organized into one duplex structure. Since colony-forming ability was used as the means of assay, it is possible to compare these experiments with those in which DNA segregation is examined on a structural basis.