by Roberto — That plas­mids are au­tonomous repli­cat­ing el­e­ments and that they can serve as ex­cel­lent cloning vec­tors are facts most cer­tainly well-known to STC read­ers. How­ever, I ven­ture to guess that the same can­not be said about the his­tor­i­cal de­tails of the when, how, and why...