 ; others ( Lorne MacHattie and Garret Ihler ) were located in the laboratory of Charles Thomas.The procedure used was devised by Garret Ihler and Karin Ippen.Complementary strands of the gene, carried within non-complementary strands of viral DNA, from viruses transducing the gene in reverse orientations which had been separated by a poly U,G density-gradient technique, were annealed to form double-stranded DNA.