Lysozyme enzyme crystals. Polarised light micro- graph of crystals of the enzyme lysozyme from the egg white (albumen) of a domestic chicken. One of the crystals is being extracted with a wire loop for study using X-ray crystallography. This is a technique for determining the three-dimensional structure of a molecule. The diffraction pattern produced as X-rays pass through a crystal depends on its structure. The study of the structure and function of proteins (proteomics) provides greater understanding of how organisms work. These crystals were grown at Lawrence Berkeley Laboratory, California, USA, for crystallography using the Advanced Light Source (ALS).