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Still working on mutagenesis


Using magnesium to compete with caesium: the experiment
Sydney Brenner Scientist
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However, we had this thing, and in the middle of the run the centrifuge broke down. Now, you have to spin for this very long time in order that you generate a gradient of the salt and then everything sediments. These gradients are tremendously mechanically stable, they're not thermally stable, and so we had to move the centr… we had to move this rotor from one lab… one cold room to another cold room, and we managed to do this and borrow another centrifuge and start it up again. And then it ran, and this day I will never forget, because we finally said, 'This is it', and then we had to take it out and take out these drops. I was extremely skilled at this because it was all done by hand – there were no machines, and you had to pierce the tube with a needle, and then take a rack of tubes and move it by hand, collecting drops. And what had happened was I had to carry the centrifuge from this cold room to this other place and I said, 'I'm not going on the lift because the lift will shake it', and so everybody made a path for me so that no one would come barging out of a room. Now in… in Cal Tech at that time the cooling was done by spraying water into the... into the circulating air. I came out of this cold room with this rotor walking along as though it was, you know, a great religious thing, and the water condensed on me from the cooling out, so by the time I got to the lab I was completely wet. My clothes were completely wet, I couldn't stop, I had to put the rotor down, undo the tubes, and François stood there and he said he was so nervous while I pierced the tube. The first one I did a… had a bit of a shake at the beginning so I missed the first four drops; it didn't make any difference, but finally we dispensed all of the three. Now that was actually the day at which the Democrat Party had a… the evening at which Kennedy was nominated for the Presidential election and that evening... as we dried all the drops. And that evening everybody went to the lab to listen to the radio and the television to see Kennedy receiving the nomination and we sat downstairs in the basement with our counter and we said, 'We're going to see if we receive the nomination now', and it was very nice because we… we relaxed there and the counter began to count, took a long time, print out. And we got delirious because we were saying it was you know, the curve began to rise and I said, you know, 'Ascendez, ascendez, you see it's rising'. Then it went on rising and then we thought it's time to stop so we were both shouting at this machine, 'Go down, go down, down, down', and you know the next one went up a bit, I said, 'It's less, it's less', and we were actually striving you know to bend… to bend the numbers, and then it came down, and it was absolutely… that's the experiment that made it convincing.

And of course then after that we knew we were right and… and what we had to do then was a lot of subsequent work in order to tidy up because we had to show that the same ribosomes that were programmed with these messengers were the ones that were making protein. That we had to do… I did in Cambridge when I returned for the rest of 1960 and in the winter of 1960 we wrote our paper, we submitted it to Nature at the… just before the end of the year and then we heard that Jim Watson was submitting a paper on the same thing and... you know, with his work on messenger. And so we finally agreed to wait for him, but he took about another five months and that is why the paper never appeared until May of 1961. But that I think did establish it and it's written in a very peculiar style which... no other paper has been written in that style because it proposed three models, it… that might explain how information is transferred that is where DNA made the protein, where there were a small number of ribosomes and where there is a messenger, right? And then it showed which of these... what are the expectations of these and which are eliminated. Now we had to do that because the technical side of the paper was very, very forbidding because people didn't understand about C13, you know; this was a technology that was quite hard to reproduce. So that is how the messenger came about and what is remarkable about that is that in a sense it's an experiment that had to be done at that level, because no one would ever do anything like that again and nevertheless, you know, we actually showed you could handle ribosomes, and I was very pleased in later years to see that there were people who did these experiments with density gradients on ribosomes.

South African Sydney Brenner was awarded the Nobel Prize in Physiology or Medicine in 2002. His joint discovery of messenger RNA, and, in more recent years, his development of gene cloning, sequencing and manipulation techniques along with his work for the Human Genome Project have led to his standing as a pioneer in the field of genetics and molecular biology.

Listeners: Lewis Wolpert

Lewis Wolpert is Professor of Biology as Applied to Medicine in the Department of Anatomy and Developmental Biology of University College, London. His research interests are in the mechanisms involved in the development of the embryo. He was originally trained as a civil engineer in South Africa but changed to research in cell biology at King's College, London in 1955. He was made a Fellow of the Royal Society in 1980 and awarded the CBE in 1990. He was made a Fellow of the Royal Society of Literature in 1999. He has presented science on both radio and TV and for five years was Chairman of the Committee for the Public Understanding of Science.



Listen to Lewis Wolpert at Web of Stories



Tags: Cal Tech, California Institute of Technology, Democratic Party, Cambridge University, 1960, 1961, François Jacob, JF Kennedy, James Watson

Duration: 6 minutes, 29 seconds

Date story recorded: April-May 1994

Date story went live: 24 January 2008