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