Tuesday, 19 April 2011

"Dear M": the transatlantic DNA collaboration of Maurice Wilkins and Leonard Hamilton

This week's post calls attention to a series of correspondence written in the 1950s that documents the DNA research carried by Wilkins and his group at King's College London from 1953 to1960. The correspondence is with Dr Leonard D Hamilton, a British medical researcher and pathologist based in the United States who worked for the Sloan Kettering Institute for Cancer Research and later the Brookhaven National Laboratory. He provided DNA samples to Wilkins at King's from 1952 into the 1960s. As my title suggests the two were firm friends and their letters are refreshingly candid. Although these letters do not document the breakthrough research on the structure of the double helix like the similar correspondence between Wilkins and Crick they do give us a good picture of how Wilkins coped with the news and life thereafter.

DNA Samples: Supply and Demand

In 1953, Leonard Hamilton became the principal provider of DNA for the King's team. Samples had previously been provided by a host of other international scientists such as Rudolf Signer, Erwin Chargaff and Harriet Ephrussi and there was a great pressure to produce better DNA samples now it had been established that DNA was the basis of genes.Wilkins and his team were also under pressure to provide a more detailed double helical model to confirm that the structure was correct and not an equally valid alternative structure.

Figure 1: Photocopy of a letter from Wilkins to Hamilton, dated 28 May 1953: Wilkins thanks Hamilton for the DNA sample taken from a mouse sarcoma and generally expresses an eagerness to press on with further DNA research.

 In the above letter, Wilkins shows his excitement over the diffraction image obtained using the S-180 mouse sarcoma sample. He also expresses the need for greater quantities and variant salts and solutions that becomes a constant theme of this correspondence, as this quotation from a letter from Wilkins on the 9 June 1954 reveals:

"As I thought I made clear, what we need is better DNAs and hence I was very disappointed to find all the samples you sent recently were no better than the usual quality. We have not the time to test laboriously numerous samples in the hope one might be good. The three dry samples were have had already and those in solution, owning to a lack of warning, arrived at this end and were held at the airport for several days and appear to have deteriorated". 

The problem of the supply of demand of DNA were exacerbated by the trans-Atlantic nature of the partnership. Communication was the biggest issue. Before the days of global mass-communication, the main medium for communication was by letter or telegram (international telephone calls had only recently been introduced and were very expensive). The frustration was felt on both sides of the Atlantic especially with the additional pressures of journal and conference deadlines. Despite these stresses, they made progress as this quote from Wilkins on 5 November 1954 states:

"The 10 week exposure came off today and is a great success. it is one of the biggest improvements we have ever had in A pictures and is very much better than the best before. Will send a copy soon and I hope I will spur you on to even better things...Good old Leonard!"

Living in the Shadow of the Watson-Crick Model

One of the reasons why these letters make compelling reading is the scattered references to the discovery of the Double Helix. In the letters we get a contemporary commentary on the initial impact of the discovery and personal opinions on some of the key characters such as Francis Crick, James Watson and Rosalind Franklin. Of particular interest is the response of Hamilton who considered that Wilkins and King's College London Biophysics Unit had been hard done by Watson and Crick's model.

Figure 2: Letter from Leonard Hamilton to Wilkins dated October 12 1954: In this letter, Hamilton describes a visit from Rosalind Franklin and also his plan to air off a little "pro-Wilkins propaganda!" at a nucleic acids conference. 
 From the correspondence, it is clear that the battles and wounds caused by the discovery are still fresh but the scientific interest in the findings ( such as the journal Scientific American in Figure 2) are already calling for a narrative of the discovery. Hamilton's repeated opposition to calling the double helix the Watson-Crick model is an example of this increasing scientific interest and his own attempts to inform the American scientific community of the role that King's Biophysics Unit played in its creation. 

Wilkins' own initial thoughts and feelings were somewhat more ambigious. For example, his assessment of Francis Crick in the letter shown in Figure 1 states:

"Taken the Watson Crick model with a grain of salt. Francis is quite certain he can solve all the problems of the universe by pure thought and his lack of facts had lost him many friends temporarily until he recovers from DNA hysteria. I am very fond of Francis but he can be a bit much at times and he can be a ruthless careerist when he thinks it suits him. but keep that quiet to ourselves. We both like him a lot so there is no harm saying this to you".

His reaction is in line with his famous letter to Crick on hearing the discovery where he called Crick and Watson a couple of "old rogues" but accepted the model gracefully. Yet in this letter he does admit a degree of resentment over the Crick's "careerist" tendencies but not enough to irreprecibly damage their friendship. 

Finals thoughts

The correspondence between these two friends is of great reading for anyone interested in the story of the double helix and the DNA research carried out at King's College London. By being both a commentary and account of the DNA research undertaken at King's in the fifties the letters acts as an informal guide to the work being carried out and excellent source of information of the different DNA salts and samples. For me, however, the best aspect of the letters is the openess and informality that Wilkins shares with his friend about his life and research.  

Figure 3: Leonard Hamilton and Maurice Wilkins together in the 1960s.

Final words

"Do please reply soon. The nature of the gene depends on it. What piffle. M"