Persistence of Vision: crystallography

 

X-ray crystallography and incredibly powerful scientific tool used to identify the atomic and molecular structure of crystals. When matter is converted into this organised crystalline state and then exposed to a beam of incident X-rays, these diffract along many different, but specific paths. After measuring the angles and intensities of these diffracted X-rays, a three-dimensional picture of the density of electrons within the crystal can be generated. This electron density map can then be used to determine the positions of the atoms in the crystal, their arrangement, and their linking chemical bonds.

Proteins and nucleic acids can be coaxed into forming crystals, and thus X-ray crystallography has been used to determine the structure of these important biological molecules. Using the process, John Kendrew in 1958 unveiled the first protein structure ever to be seen by humankind, that of the protein Myoglobin, and then later in 1959 Max Perutz employed the same method to determine the molecular structure of Haemoglobin. Since these landmark achievements the structures of DNA, RNA, and over 90,000 proteins have been determined using X-ray crystallography, providing incredible insights into the molecular workings of life.

In this context of the above, I’ve had an obsession with the process of crystallisation ever since I read JG Ballard’s The Crystal World as a teenager. Here, I’m exploring this same crystallisation process and biology at a microscopic scale, and so I’ve mixed a culture of my own epithelial cells with a solution of urea. At first the molecules of urea move around my cells in a frenzied and random dance, but soon they start to slow down, and thus begin to recognise each other, and as they join together, this initiates an almost explosive crystallization event that rapidly consumes these minute parts of me. As they would be prior to analysis by X-ray crystallography, the protein and nucleic acids in my cells have been converted into crystals, yet they and their information is still preserved in persistent and recognisable islands, in a micrometre thin continuum of chemistry and life.

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