Photo 51

Rosalind Elsie Franklin (25 July 1920 – 16 April 1958), English chemist and X-ray crystallographer.

Nowadays when the subject of DNA structure comes up, one immediately thinks of James Watson and Francis Crick. While their work in revealing the structure of DNA must certainly be acknowledged, there is a third name that should rightly be associated with the discovery: Rosalind Franklin.

Known best for her x-ray crystallography expertise and work on coal, graphite and the Tobacco Mosaic Virus, Franklin was the one who worked out the two different forms of DNA. By developing a method for separating the two forms, Franklin made a number of important discoveries, chief among them that the sugar-phosphate backbone of DNA was on the outside of the molecule (and not inside, as previously thought), and that the helical structure of DNA had two strands, not three. Her x-ray diffraction photograph of crystalline B-form DNA is simply known as Photo 51, and is described as "amongst the most beautiful x-ray photographs of any substance ever taken."

The structure of DNA had almost been completely deciphered, but for one missing piece of the puzzle: how the bases paired up inside the helix.

Following John Randall's presentation of Franklin's data and unpublished conclusions at a routine seminar, her fellow researcher Maurice Wilkins showed the results to Watson and Crick, without either Randall or Franklin's knowledge. Based on Wilkins' help in deciphering the photograph and chemical information supplied by chemist Jerry Donohue, James Watson was able to work out the missing piece. Watson and Crick's write-up of the structure of DNA was published in the April 1953 edition of Nature, alongside Franklin's own report. Franklin was never aware of the fact that the duo had had access to her results. [Francis Crick later estimated that she might have worked out the complete structure on her own in three months, had they not gotten hold of her data.]

Watson and Crick won the 1962 Nobel Prize for Physiology and Medicine for their work "concerning the molecular structure of nucleic acids and its significance for information transfer in living material". By then, Franklin had been dead for four years, from ovarian cancer. She was 37 years old.

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Technical Notes:

Colour pencils (ivory, brown, Vandyke brown, black, touch of vermillion) on brown card. It seemed a crime to draw her portrait in technicolour, and an even greater one with digital paint!! Yes, it's meant to look faded (I really wanted the colours to "emerge" from the paper and not pop out of it); this is actually pretty close to my original version, only my scanner inexplicably gave the picture a pink glow that I could not remove.