X-ray – More Than A Dodo

by Imran Rahman, Deputy Head of Research

There are plenty of reasons to visit Didcot. The railway station is an important junction between Oxford and the west of England, the Didcot Railway Centre houses a great collection of trains, if you like that sort of thing, and Didcot Town Football Club are currently a respectable fourth* in Division One West of the Southern League…

But if that’s not enough to tempt you, Didcot is also home to the UK’s only synchrotron – a multi-million pound facility that goes by the name of Diamond Light Source. In February, six members of the Museum’s research team visited Diamond to carry out some important experiments on spiders.

But before we get to that, what exactly is a synchrotron light source? Well, it is a type of particle accelerator which uses huge magnets to speed up tiny particles, usually electrons, until they are moving almost as quickly as the speed of light. The particles are sent flying around a ring-shaped machine hundreds of metres across – the ‘doughnut’ structure in the photo.

The Diamond Light Source synchrotron in Didcot, Oxfordshire. Particles are accelerated to close to the speed of light around the ‘doughnut’ structure. Image: Courtesy of Diamond Light Source

This beam of high-energy particles gives off large amounts of ‘light’, or electromagnetic radiation, when its direction is changed. This radiation, usually in the form of X-rays, can be funnelled down to experimental stations, known as beamlines, and used for lots of different measurements and experiments. As the UK’s national synchrotron light source, Diamond is visited by scientists from all over the world every year.

So what does a museum want with a powerful X-ray beam? One of our research fellows, Lauren Sumner-Rooney, is particularly interested in studying the eyes and brains of spiders. So the team, led by Lauren, went to Didcot to create some X-ray images of spiders from the Museum’s collections.

Ready for your X-ray close -up? A spider specimen is mounted in the I13-2 beamline at Diamond Light Source. Image: Lauren Sumner-Rooney

You may not have looked too closely at a spider’s head before, but they usually have eight eyes as well as eight legs. That said, there is actually quite a lot of variation in the number and structure of eyes between different species, and Lauren is interested in documenting this variation across selected spider families to investigate how it affects spiders’ brain structures.

Using the I13-2 beamline at Diamond, and fighting severe sleep deprivation with the aid of strategically-selected songs and snacks, the team was able to visualize details measuring less than one thousandth of a millimetre without damaging the precious specimens. They were assisted by Andrew Bodey, a senior support scientist at Diamond, and Emelie Brodrick, a PhD student at the University of Bristol.

The research team following 72 hours of very little sleep! From left to right: Ricardo Pérez-de la Fuente, Lauren Sumner-Rooney, Imran Rahman, Jack Matthews and Emelie Brodrick. Image: Emelie Brodrick

Over the course of 72 straight hours, the team scanned 116 spiders, creating about 14 terabytes of data. This will form the basis of a variety of exciting scientific research projects at the Museum over the coming years. Watch this space for the results!

*Didcot Town were fourth in the Southern League Division One West table on 8^th March. The Museum accepts no responsibility for any change in their position after this date.

Top image of Pholcus moca courtesy of Smithsonian Institution.

‘A thoroughly unhousewifely skill’

For International Women’s Day, the Museum of Natural History celebrates the life and career of Dorothy Hodgkin, one of its most eminent researchers. Hodgkin was awarded the Nobel Prize for Chemistry in 1964, and is still the only UK woman to have been awarded one of the science Nobels.

When the Museum of Natural History was designed in the 1850s, the building was intended not just to house a museum but also the burgeoning science departments of the University. The lettering above the doors facing the court continues to record these early affiliations: ‘Department of Medicine’, ‘Professor of Experimental Philosophy’, and so on.

Dorothy_Hodgkin_Nobel — Dorothy Mary Hodgkin (1910–1994) Image: Nobel Prize

As individual departments grew they moved into their own buildings across the science campus. One of the last research groups left in the Museum was the Department of Mineralogy & Crystallography, which, from the 1930s onwards, was the research home of the outstanding X-ray crystallographer Dorothy Hodgkin (1910-1994), winner of the Nobel Prize for Chemistry in 1964.

The Daily Mail famously celebrated her success with the headline ‘Oxford housewife wins Nobel’, but The Observer was no more enlightened, commenting that Hodgkin was ‘an affable looking housewife’ who had been awarded the Nobel Prize for ‘a thoroughly unhousewifely skill’. That socially disruptive ability was an unparalleled proficiency with X-ray analysis, particularly in the elucidation of the structure of biological molecules.

Hodgkin undertook her first degree at Oxford from 1928 to 1932, initially combining chemistry and archaeology but later focusing on the emerging technique of X-ray crystallography. Her undergraduate research project was carried out using this technique in a Museum laboratory within what is now the Huxley Room, the scene of the 1860 Great Debate on evolution between Bishop Wilberforce and T. H. Huxley. She then journeyed across to Cambridge for her PhD before returning to Oxford in 1934 and resuming her association with the Museum.

Model_of_the_Structure_of_Penicillin,_by_Dorothy_Hodgkin,_Oxford,_c.1945 — Model of the Structure of Penicillin, by Dorothy Hodgkin, Oxford, c.1945, in the Museum of the History of Science

Back in Oxford, Hodgkin started fundraising for X-ray apparatus to explore the molecular structure of biologically interesting molecules. One of the first to attract her attention was insulin, the structure of which took over 30 years to resolve – a project timescale unlikely to appeal to modern research funders. Other molecules proved more tractable, including the newly discovered penicillin, which Hodgkin began to work on during the Second World War, and vitamin B₁₂. It was for the determination of these structures that she was awarded the Nobel Prize.

Dorothy Hodgkin’s new X-ray laboratory was set up in a semi-basement room in the north-west corner of the Museum. The room is now a vertebrate store but was once also the research home of Prince Fumihito of Japan, when he was based in the Museum for his ichthyological research (and It is still the only room in the Museum with bulletproof windows).

Initially, Hodgkin’s only office space consisted of a table in this room and a small mezzanine gallery above, which housed her microscopes for specimen preparation. Once prepared, she then had to descend a steep, rail-less ladder holding the delicate sample to the X-ray equipment below. Later, Hodgkin had a desk in the ‘calculating room’ (now housing the public engagement team) where three researchers and all of their students sat and undertook by hand the complex mathematics necessary after each analysis to determine the crystal structures of organic molecules.

Paul Smith – Director

If you would like to learn more about Dorothy Hodgkin and her work, then read Georgina Ferry’s excellent biography ‘Dorothy Hodgkin: A Life’ which has just been re-issued as an e-book and new, print-on-demand paperback by Bloomsbury Reader.

This year’s Dorothy Hodgkin Memorial Lecture will be held in the Museum at 5 pm on Thursday 12 March, and is open to all. The lecture will be given by Dr Petra Fromme (Arizona State University) who is an international authority on the structure of membrane proteins.

Tag: X-ray

Spiders’ eyes cast in Diamond Light

‘A thoroughly unhousewifely skill’