Racemic crystallography is a technique used in structural biology where crystals of a protein molecule are developed from an equimolar mixture of an L-protein molecule of natural chirality  and its D-protein mirror image. L-protein molecules consist of left-handed L-amino acids and the achiral amino acid glycine, whereas the mirror image D-protein molecules consist of right-handed D-amino acids and glycine. Typically, both the L-protein and the D-protein are prepared by total chemical synthesis.