Letter from Gordon L. Ada to Joshua Lederberg Note from creator: I worked at the Walter and Eliza Hall Institute, Melbourne from 1948-1968. Macfarlane Burnet was Director for most of that time. Until 1957, everyone worked on the influenza virus as Burnet was the world's expert. In 1957, Burnet came out with a new concept in Immunology, the Clonal Selection Theory, and had decided all would switch to an immunology topic. At that time Josh Lederberg arrived for a visit. He wanted to influenza virus genetics with Burnet but Burnet was no longer interested. So he started talking to other members of the Department. The influenza virus has an enzyme, neuraminidase, on its surface. Vibrio cholerae produces a similar enzyme which I thought I would try to purify. We grew the bacteria in a broth but Josh advised that I should grow the bacteria in a synthetic medium (no protein) as then it would be much easier to purify the enzyme. But when I did this, no enzyme was produced. I had to find a source of a substrate to add to the medium, but at this stage, we did not know the specificity of the enzyme. I found my wife's breast milk (she had recently had a baby) was a good source of substrates, even some substrate being dialysable. I found I could obtain lots of cow's colostrum from a farmer who bred cows. I dialysed it against the synthetic medium and now, using the dialysate, lots of neuraminidase was formed. We were then able to purify and crystallize the enzyme. Produced: 6 September 1977 John Curtin School of Medical Research The Australian National University. John Curtin School of Medical Research Ada, Gordon L. Letters (correspondence) Archival Materials Text 1 pages nlm:nlmuid-101584906X8653-doc 101584906X8653 http://resource.nlm.nih.gov/101584906X8653 Profiles ID: BBAMXN English Profiles in Science