Question: what is crystallography?

Allan Pang answered on 26 Jun 2012:

Crystallography is the science of the arrangement of atoms in solids.

In my case, the field/area I am on is called Protein Crystallography.

The basic principle is we cannot view proteins (in atomic level) under light microscope and therefore to get around this problem, we have to turn protein solution into a solid form. This solid form or protein crystal can be shot by an X-ray beam and produces a pattern, which we can interpret it using complex maths and know the exact position of each atom of a protein.

To make protein crystal, we mix our protein solution with different precipitants (precipitants are chemicals that pushes protein to a solid state). Proteins then come together in orderly manner and become crystals. The crystals we got can only be viewed under microscope, because they are quite tiny.

Hope that helps!