A technique for finding the structures of molecules. It was pioneered with simple structures (~10 carbon atoms), but really took off when BioChemist''''''s applied it to proteins. The largest structure solved to date (in 1999) was the bluetongue virus - roughly a sphere 70 nm across, with 1008 separate protein molecules and 10 DNA strands.

Protein structures determined using XrayCrystallography and NuclearMagneticResonance (a rival technique which is quicker and more biologically useful, but which only works for fairly small proteins) are deposited in the ProteinDataBank.