Wyatt, Gerard R. (1925-)

  • Wyatt, Gerard R.,1925-.
  • Archives and manuscripts

About this work


Laboratory notebooks, correspondence and other papers of Gerard R. Wyatt, related to his research on nucleic acids, including DNA, between 1949 and 1955.



Physical description

2 boxes


The collection is divided into sections as follows:

A: Laboratory notebooks, in chronological order.

B: Files, including correspondence with Seymour Cohen.

Acquisition note

Presented to the library at Wellcome Collection by Professor Wyatt, May 2003.

Biographical note

Gerard Wyatt was born in the U.S. in 1925 and from 1935 settled in Canada. From 1947 to 1950 he was a research student at the Molteno Institute, Cambridge, where (influenced by Roy Markham) he undertook quantative base analyses of DNA as his Ph.D. research. He identified 5-methylcytosine as a component of eukaryotic DNAs and did paper chromatography analyses that indicated equality of A and T and of G and C. This work was carried out at the same time that Erwin Chargaff's lab was reaching similar conclusions, but Wyatt's work was felt to use better techniques.

After moving to the Canadian government Laboratory of Insect Pathology in Sault-Ste.Marie, Wyatt followed up this work with the identification, together with Seymour Cohen, of 5-hydroxymethylcytosine in T-even phage DNA, and analyses of a set of baculoviruses that showed the base pairing particularly clearly. (Seymour Cohen was one of a group of bacteriophage scientists at Cold Spring Harbor laboratory in the 1940s and 1950s, headed by Max Delbrück and also including Salva Luria and Al Hershey; correspondence between Cohen - then in Philadelphia - and Wyatt forms part of the Wyatt papers.) According to a paper by A. Marshak (PNAS 37, 299, 1951), the T2, T4 and T6 group of phages lacked cytosine, which would have made the double-helix model impossible: Wyatt's demonstration that they contained the modified form 5-hydroxymethylcytosine and that this was in equal quantities to guanine thus removed an obstacle to the double-helix model.

Wyatt published several articles drawing upon this work:

Nature 166, 237 (1950); Biochemical Journal 48, 581 and 584 (1951); Biochemical Journal 49, 144 (1951); Journal of General Physiology 36, 210 (1952); Nature 170, 1072 (1952); Biochemical Journal 55, 774 (1953). The Journal of General Physiology paper is cited in Watson and Crick's April 1953 Nature article proposing the double-helix structure of DNA, and James Watson cites Wyatt's work in The Double Helix (London: Weidenfeld & Nicolson, 1968), p.170. The accounts of DNA discovery by Robert Olby (The path to the double helix: the discovery of DNA (New York: Dover Publications, 1994)) and Horace Judson (The eighth day of creation: makers of the revolution in biology (New York: Simon and Schuster, 1979)) discuss Wyatt's contribution.

Wyatt did not follow up his DNA research in his career, concentrating instead on the biochemistry of insects.

Related material

At Wellcome Collection:

The papers of Francis Crick (PP/CRI) are a key resource on the search for the structure of DNA.

Location of duplicates

A digitised copy is held by Wellcome Collection as part of Codebreakers: Makers of Modern Genetics.

Where to find it

  • LocationStatusAccess
    Closed stores
    OpenCan't be requested

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Accession number

  • 2465
  • 1163