Doctors warned that the chances of finding a compatible donor were slim but, after a short search, her grandmother turned out to be a match.

The technique involves injection of compatible donor red blood cells of a different blood group into a recipient, followed by blood testing periodically afterwards.

These modifications can be driven to completion in case the compatible donor plasmid(s) are provided at an excess (mass-action principles).

The tra genes encode proteins which are useful for the propagation of the plasmid from the host cell to a compatible donor cell or maintenance of the plasmid.