A process for cloning DNA into a suitable host, which comprises fragmenting said DNA to obtain fragmented DNA, ligating said fragmented DNA into a suitable vector to obtain chimeric (hybrid) DNA, and transforming said chimeric DNA into said ultimate host. By this process, the useful chemical plasmid pUC3, which is obtainable from a biologically pure culture of the microorganism Streptomyces sp. 3022a, NRRL 11441, is cloned into the well-known bacterium E. coli HB101. This cloning of pUC3 into E. coli HB101 enables the production of large amounts of plasmid pUC3 DNA. pUC3 is useful as a cloning vehicle in recombinant DNA work. For example, using recombinant DNA methodology, a desired gene, for example, the insulin gene, can be inserted into pUC3 and the resulting plasmid can then be transformed into a suitable host microbe which, upon culturing, produces the desired insulin.