Plasmid incompatibility

There can be more than one different type of plasmid in a cell, as exemplified by wild types of Borrelia  burgdorferi, which carry  17 circular and  linear plasmids. In common with the bacteriophages and other viruses, some plasmids have evolved mechanisms to repel reinfection by different types of plasmid. When this occurs, the two plasmids are said to be incompatible. Testing which plasmids are compatible with which gives a table of plasmid incompatibility groups. This can be useful to the biotechnologist who may wish to introduce recombinant genes in successive experiments.