The contruction and replication properties of hybrid plasmids composed of the r-determinant of R100.1 and the plasmids pCRI and pSC201.

We have cloned the entire r-determinant of the antibiotic resistance plasmid R100.1 on the plasmic vectors pCR1 and pSC201. We find that the hybrid plasmids segregate from cultures in which replication of the vector is blocked. This suggests that the r-det is not capable of autonomous replication.