And that job was very interesting. The goal of the work that I was doing was to be involved in an assay for an enzyme that destroyed blood clots. And this enzyme was produced by a streptococcus that we grew in huge tanks, tanks a couple of... at least at that time, huge – they're much bigger today – about three metres high and holding maybe 1,000 litres of fluid, in which we grew this organism and then it was processed in order to extract the enzyme we were interested in. This was a pathogenic organism, so that we had to worry very much about aseptic techniques, that is, sterile techniques, techniques to prevent ourselves from being exposed to this organism.

And all of that added up to a very, very interesting experience that I... was carried over, of course, when we moved from that point to Merck's facilities in North Wales, Pennsylvania, right north of Philadelphia. And that facility was... had just been built, it was a huge horseshoe shaped building, state of the art research laboratories in which I was now a part of one. And my boss was a very nice fellow, a man by the name of Aaron Wasserman, who had spent his military career in Europe and trained in the UK and, in fact, married a British woman. He was a wonderful guy; he encouraged me in my interest in microbiology, as did his boss, who was the department chairman, a man by the name of Willard Verwey, both of whom were very influential in my love of microbiology. I also met several other people there, one of whom was a virologist, and people who were involved in biochemistry. So my interests began to become even more expanded than they were.

By this time, since I still had some... I still had some friends at Penn who had gone on to get a Master's Degree, and some of them even were pursuing a PhD, I had not done that, first of all because of financial considerations, but more importantly, as I recall, I did not feel that I had the ability to obtain a Master's Degree or a PhD. And I don't know what that... what kind of message that sends, but that's how I felt about myself. I just looked and had experience now with some PhDs at Merck and just thought their broad knowledge was so great that I could never achieve that level of understanding.