The scientific career of Maurice Wilkins did not solely focus on the structure and refinement of DNA. Having begun reading Physics at Cambridge in 1936, Wilkins went on to work on luminosity and phosphorescence and made contributions to wartime radar research in Birmingham and later at the University of California, Berkeley, on the Manhattan Project to develop the first atomic bomb. After reading Erwin Schrödinger’s seminal “What is Life?” (1944), which influenced a generation of scientists, and following a period of soul-searching following the atomic bombing of Hiroshima and Nagasaki, Wilkins decided to focus his research on biophysics – the use of physics to study biological structures. He began his work by investigating the effect of ultrasonics on chromosomes.
Wilkins’ began research on the biological implications of ultrasonic technology when he first moved back to the UK after his wartime experience in America. Whilst at St Andrews, he was talking to the Glasgow University-based geneticist, Charlotte Averback, about Hermann Muller’s work using x-rays to cause mutations within fruit flies and he wondered whether he could replicate it using another physical agent. As Wilkins states in the The Third Man of the Double Helix (2003):
“No-one seemed to have tried strong high frequency sound (ultrasonics) on chromosomes...it was a way of starting [in biophysics]; I could do it on my own and it might help us to understand how genes worked” (p91)
The aim of his experiments was to explore the effects of ultrasonics on a living cell nucleus and especially its effect on the process of mitosis. The hope was that the ultrasonics ray would cause breakage of the chromosome and provide an interesting comparison with similar breaks engendered by other agents such as x-rays.
The initial experiments typified Wilkins’ approach to science, as he constructed by himself a high power ultrasonic generator for the experiments. A paper produced by G G Selman and Wilkins published in July 1949, states that their high intensity ultrasonic apparatus could “generate and measure higher unfocused ultrasonic intensities than any we have yet found recorded in the literature” (p229, G. G. Selman & M. H. F Wilkins, "The production of high intensity ultrasonics at megacycle frequencies” in Journal of Scientific Instruments, Volume 26).
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Yet results proved disappointing: no evidence of the cytogenetical effects of ultrasonics were found despite using an array of different samples including root tips, chick heart fibroblasts and Tradescantia pollen tubes.
Wilkins was soon keen to move onto other projects when he realised pursuing ultrasonics was not worthwhile and he was asked by John Randall to take over research into how DNA moved and grew in living cells. It was this shift into microscope studies of DNA that would lead Wilkins to recognise the potential of x-ray diffraction to elucidate the structure of the molecule.
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