Astbury, William (Bill) (1898–1961)
English crystallographer who was fascinated by the ‘fabrics of Nature’ and the molecular structure of fibres, and introduced the term ‘molecular biology’. His team in the Department of Biomolecular Structure in Leeds took early X-ray photographs of DNA (see Elwyn Beighton). Astbury believed that DNA acted as a direct template for protein synthesis and that its structure was too simple to carry genetic information.
Avery, Oswald T. (1877–1955)
Bacteriologist, biochemist and expert on pneumococci, the bacteria that cause lobar pneumonia. Led the group at the Rockefeller Institute for Medical Research, New York, which proved that DNA was the ‘transforming factor’ which could alter the genetic characteristics of pneumococci under laboratory conditions. A conspicuous non-recipient of a Nobel Prize.
Beighton, Elwyn (1919–2007)
One of Bill Astbury’s PhD students, notionally working on bacterial flagella. In May 1951, took an X-ray photograph of wet DNA fibres (B299), which showed the same X-shaped pattern of a helical molecule as in Ray Gosling’s famous Photograph 51, taken a year later. B299 was never published or presented.
Bernal, John Desmond (1901–71)
Nicknamed ‘Sage’ for his apparent omniscience. Charismatic polymath, impossible to summarise in a few lines. Passionate about X-ray crystallography, women, unexploded bombs, art and everything Soviet. Directed the Crystallography Department at Birkbeck College, London, where Rosalind Franklin worked on the structure of viruses after leaving her research into DNA at King’s College in early 1953.
Bragg, Sir Lawrence FRS (1890–1971)
The youngest ever recipient (aged 25) of a scientific Nobel Prize, jointly with his father in 1916. Formulated Bragg’s Law, one of the basic tenets of X-ray crystallography. Professor of Physics and Director of the Cavendish Laboratory in Cambridge from 1938 to 1954. His research group included the MRC Unit for the Study of the Molecular Structure of Biological Systems, led by Max Perutz, which recruited Francis Crick (1949) and James Watson (1951).
Bragg, Sir William FRS (1862–1942)
One of the fathers of X-ray crystallography. With his son Lawrence, won the 1916 Nobel Prize for Physics for deciphering the structures of numerous salts and minerals. While President of the Royal Institution in London during the 1930s, trained Bill Astbury and J.D. Bernal in X-ray crystallography.
Chargaff, Erwin (1905–2002)
Ukrainian-born American biochemist and erudite critic of the scientific scene and the world at large. While investigating the composition of DNA from different sources, noticed that the contents of adenine and thymine were identical, as were those of cytosine and guanine (‘Chargaff’s Law’). He was scathing about the contributions of Watson and Crick and felt that his own discovery was worthy of a Nobel Prize.
Creeth, Michael (1924–2010)
One of Masson Gulland’s PhD students in Nottingham, whose studies of the physical and chemical properties of DNA provided evidence that the molecule was held together by hydrogen bonds between bases. Creeth suggested in his unpublished PhD thesis (1947) that DNA was a double-stranded molecule, with the strands bridged by hydrogen bonds between bases on the opposing chains.
Crick, Francis (1916–2004)
‘Tall, fair and very English’ physicist, biochemist and eventually neuroscientist. Rescued from an ‘unimaginably dull’ research project by a Luftwaffe bomb, he went to work at the Cavendish Laboratory in Cambridge on the structure of proteins. There, he met Jim Watson, who fired his interest in solving the structure of DNA. Their paper on the double helix was published in Nature in 1953, before Crick finished his PhD.
Flemming, Walther (1843–1905)
German microscopist and Professor of Anatomy at Kiel University, who deciphered the movements of chromosomes during cell division (which he called ‘mitosis’) in tissues of the fire salamander. Coined the term ‘chromatin’ for the heavily stained substance of chromosomes and suggested that this was identical to Friedrich Miescher’s nuclein.
Franklin, Rosalind (1920–58)
English X-ray crystallographer who was best known during her lifetime for her research into the structures of coal and viruses. While working in John Randall’s Biophysics Unit at King’s College, London, she identified the A and B forms of DNA; her PhD student Ray Gosling took the celebrated ‘Photograph 51’, demonstrating the helical structure of the B form. Franklin generated most of the data used by Watson and Crick to derive the double helix, and was seen as coming ‘within two half-steps’ of solving the structure herself.
Furberg, Sven (1920–83)
Swedish biochemist who learned X-ray crystallography for a PhD with J.D. Bernal. Worked out how the bases are joined to the sugar, deoxyribose, and proposed in his unpublished PhD thesis (1949) that DNA was a helical, single-stranded molecule.
Gosling, Ray (1926–2015)
While a PhD student at King’s, worked with both Maurice Wilkins and Rosalind Franklin. Took two classic X-ray photographs of DNA: the ‘crystalline’ image which inspired Watson to pursue the structure of DNA, and ‘Photograph 51’, which confirmed the helical nature of the molecule. Later, worked with Franklin to define the A (crystalline) and B (helical) forms of DNA.
Griffith, Fred (1879–1941)
Reclusive English bacteriologist who worked in a government service laboratory in London; hated scientific meetings and published infrequently. In 1928, described ‘transformation’ of pneumococci – the first transfer of genetic material between living organisms achieved in the laboratory. Avery later showed that the ‘transforming principle’ responsible was DNA.
Gulland, Masson (1898–1947)
Scottish biochemist whose lifetime ambition was to return to Edinburgh as Professor of Biochemistry. His research interests ranged from the nucleic acids to the use of Scottish seaweed to make waterproof clothing. While Professor of Biochemistry in Sheffield, supervised research which showed that the DNA molecule was held together by hydrogen bonds between the bases.
Kossel, Albrecht (1853–1927)
German biochemist and man of principle who devoted his career to finding the building-blocks (Bausteine) of large, biologically important molecules, including the nucleic acids. Awarded the Nobel Prize in Chemistry (1910), mainly for his work on the proteins associated with DNA in the nucleus. His major book (published posthumously) on components of the nucleus concluded that DNA was less important than proteins, and so helped to undermine interest in its role in heredity.
Levene, Phoebus (1869–1940)
Russian-born American biochemist who worked at the Rockefeller from 1915 until the day before his death. Prolific researcher who ‘left no part of biochemistry’ untouched. Did seminal work on the components of DNA and wrote the influential book Nucleic Acids (1928). Became convinced that DNA consisted of repeating units containing one each of the four bases. This ‘tetranucleotide hypothesis’ implied that the structure of DNA was too dull to carry genetic information – an assumption that obstructed DNA research for over 30 years.
MacLeod, Colin (1909–72)
Canadian-born physician and bacteriologist who worked with Oswald Avery at the Rockefeller (1939–41) on the ‘transforming principle’ which could change the genetic characteristics of pneumococci. Found that the transforming principle contained deoxyribose, the diagnostic sugar of DNA, but failed to follow this up. Co-author on Avery’s paper (1944) demonstrating that the transforming principle was DNA, and therefore that DNA was the genetic material in pneumococci.
McCarty, Maclyn (1911–2005)
American physician, biochemist and bacteriologist who followed MacLeod in Avery’s lab at the Rockefeller. Performed the key experiments to prove that the transforming principle was DNA and therefore the genetic material in pneumococci; third author on Avery’s seminal 1944 paper. Regarded by many as ‘a scientist’s scientist’.
Mendel, Gregor (1822–1884)
Brother and later Abbot of the Augustinian Abbey of St Thomas in Brünn, Austrian Empire (Brno in the present-day Czech Republic). Wide-ranging research interests, notably meteorology and plant-breeding. Formulated the basic rules of inheritance, based on seven years of experiments on garden peas, in his ‘Studies of plant hybridisation’ (1866). Mendel’s work was essentially ignored until 1900, when it was ‘rediscovered’ almost simultaneously by three academic botanists; the acrimonious debate that followed included accusations that Mendel had faked his results.
Miescher, Friedrich (1844–1895)
Swiss doctor forced into biochemistry because deafness prevented him from practising as a clinician. In 1868, discovered a novel substance in extracts of white blood cells harvested from pus-soaked bandages. Miescher showed that the substance was acidic, rich in phosphorus and came from the nucleus – hence his name ‘nuclein’ – but argued that it played no role in heredity. Nuclein was later renamed ‘thymonucleic acid’ and then deoxyribonucleic acid (DNA).
Mirsky, Alfred (1900–74)
American biochemist and world expert on nucleic acids. Isolated ‘chromosin’ from cell nuclei, as white fibres that could be wound around a rod like candy floss, and showed that it consisted of DNA associated with protein. Mirsky was convinced that genes could only be made of protein and dedicated himself to attacking the evidence from Avery and others that DNA was the genetic material.
Morgan, Thomas Hunt (1866–1945)
American zoologist and geneticist, initially sceptical about Mendel’s findings and the role of chromosomes, but was converted by his own experiments on the inheritance of mutations in the fruit fly, Drosophila. Led research in the Fly Room at Columbia University, New York; co-wrote The Mechanism of Mendelian Inheritance (1915) and won the first Nobel Prize for genetics (1933).
Pauling, Linus (1901–94)
American chemist, peace activist, polymath and showman of whom it was said: ‘His name will be remembered for as long as there is a science of chemistry.’ Wrote the bestselling The Nature of the Chemical Bond (1939) and described the alpha-helix, which determines the shape of proteins; also suggested a woefully erroneous structure for DNA (1952). Won Nobel Prizes for Chemistry (1954) and Peace (1962).
Randall, John (1905–84)
English physicist and lead inventor of the cavity magnetron, a revolutionary radar component which was decisive in winning air and sea campaigns during the Second World War. Founded (1946) and led the Biophysics Unit at King’s College, London, where Maurice Wilkins (his former PhD student) and Rosalind Franklin worked independently on the structure of DNA. Randall’s management style was described as ‘Napoleonic’ and ‘divide and conquer’, and was instrumental in preventing Wilkins and Franklin from collaborating.
Sutton, Walter (1877–1916)
American surgeon who did a PhD on cell division in the grasshopper, before giving up genetic research for clinical practice. Formulated the ‘Chromosome Theory of Heredity’, postulating that the hereditary ‘factors’ identified by Mendel are situated on the chromosomes.
Vavilov, Nikolai (1887–1943)
Russian botanist and geneticist, regarded internationally as one of Russia’s greatest scientists. Famous for his work on the genetics of wheat and his attempts to improve wheat yields using Mendelian principles. Fell foul of Trofim Lysenko, third-rate researcher and top-class political animal, who detested Mendelism and classic genetics. In 1940, Vavilov was arrested during a plant-collecting trip; his fate was not known until after the war.
Watson, James D. (Jim) (born 1928)
Child prodigy, with encyclopaedic knowledge of ornithology; went to university aged 15 and was awarded his PhD at 23. Inspired to understand the gene by reading What is Life? by Erwin Shrödinger, and to crack the structure of DNA by hearing Maurice Wilkins talk about the crystalline nature of DNA. On moving to the Cavendish Laboratory, Cambridge in 1951, persuaded Francis Crick to focus on solving the structure of DNA. Watson spotted the crucial linkages that hold together the bases in the two strands of DNA, which led directly to the structure of the double helix. Shared the Nobel Prize (1962) with Crick and Wilkins, and wrote his controversial personal account, The Double Helix (1968).
Wilkins, Maurice (1916–2004)
English physicist and contemporary of Francis Crick. After war work on radar screens (as John Randall’s PhD student) and the atom bomb, became Randall’s deputy in the Biophysics Unit at King’s. Studied DNA as fibres and in the heads of spermatozoa, using optical methods and X-ray diffraction. Wilkins’s description of crystalline DNA galvanised Jim Watson to crack the structure of the molecule. Wilkins shared the Nobel Prize (1962) with Watson and Crick – but were his publishers right to subtitle his autobiography ‘The Third Man of the Double Helix’?