The invention described herein pertains to the production of closed-end double-stranded DNA (cdsDNA) that can be easily amplified and produced in large quantity, for use in, for example, therapeutic use, such as gene therapy.本文所述之發明係關於可容易擴增及大量生產之封閉末端雙股DNA (cdsDNA)的產生,該封閉末端雙股DNA用於例如治療用途,諸如基因療法。