An in vitro process for the production of closed linear deoxyribonucleic acid(DNA) comprises (a) contacting aDNA template comprising at least one protelomerase target sequence with atleast one DNA polymerase in the presence of one ormore primers under conditions promoting amplification of said template; and(b) contacting amplified DNA produced in (a) withat least one protelomerase under conditions promoting production of closedlinear DNA. A kit provides components necessary inthe process.