NTP Talks Transgenics

It is indeed a pleasure and a privilege to be asked to give this lecture in memory of a fine medical scientist, whose career was cut so sadly short by violence. In looking at the program today I cannot help but think of another scientist, to whom this field owes so much, whose life was also cut short unexpectedly. Alick Isaacs, the discoverer of interferon, was a brilliant medical scientist and it is a matter of regret to us all that he did not live to see the discovery which he had made, spread so pervasively through the modern medical sciences. I was fortunate enough to work with Alick Isaacs for five years at the National Institute for Medical Research and I was working with him when interferon was discovered. At that time, I was working on the nucleic acids of influenza virus, for it was not known whether they contained RNA, DNA or both; indeed it was still the days of 'steam age' virology. Towards the end of this piece of work Alick and I were discussing what to do next when he suggested that I might work with him on something interesting that he was doing on interference. This was March 1957, shortly after the discovery of interferon, and before any of the published work had appeared. Little did I know that a casual conversation would affect my career in the way it has. Those were heady days for a young scientist; for nearly every experiment that we did was publishable. The early characterization was relatively straightforward pH 2 sensitivity, degradation by the enzymes pepsin and trypsin, ammonium sulphate precipitation, etc. It only got much harder when I started to try and purify interferon, a project which took many years of work by a number of scientists to complete. However, it is Alick himself who I remember so vividly from that period. We assayed interferon by using a haemaglutinin assay and pieces of a chick chorio-allantoic membrane. Alick and I spent hours sitting at the bench making the necessary two-fold dilutions before adding the chick red cells. During this period he gave me an education in virology. Still a relatively new science, virology had grown out of medical microbiology and indeed at that