RT Journal Article SR Electronic(1) A1 Hauman, J. H. A1 Hedges, R. W. A1 Coetzee, W. F. A1 Coetzee, J. N.YR 1982 T1 Plasmid R394 is a Cointegrate JF Microbiology, VO 128 IS 11 SP 2791 OP 2795 DO https://doi.org/10.1099/00221287-128-11-2791 PB Microbiology Society, SN 1465-2080, AB Plasmids R394a and R394b which cointegrate to form R394 are described. They have molecular masses of 102 ± 4 and 11·0 ± 0·4 MDal, belong to the T and N incompatibility groups and confer resistance to kanamycin and ampicillin, respectively. R394a is self transmissible and mobilizes R394b, which is non-self transmissible. These findings clarify anomalies in the behaviour of R394 and support suggestions based on the properties of variant phages derived from R394., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-128-11-2791