Isolation of pure lac operon DNA.

Order of authorship in the original publication: Shapiro, MacHattie, Eron, Ihler, Ippen, Beckwith. Beckwith led the research group that in 1969 isolated the first gene from an organism, specifically a gene from a bacterial chromosome. The gene they isolated was lacZ, which codes for the β-galactosidase enzyme used by E. coli bacteria to digest the sugars in milk. Their technique involved transduction to clone oppositely oriented copies of the gene inserted into two specialized transducing bacteriophages, then mixing single-stranded DNA from the two phages so that only the bacterial sequences would form a double helix, and finally using a nuclease to degrade the single-stranded phage sequences, leaving only the double-stranded lacZ DNA" (Wikipedia article on James A. Shapiro, accessed 7-22).