X-ray Diffraction of Biological Samples

X-ray diffraction or XRD is a non-destructive analytical technique used to study the structural and spatial arrangement of atoms. It is commonly used to study biological samples such as protein crystals, nucleic acids, and ribosomes. It is also used to study crystalline powders of pharmaceutical formulations.

The XRD analyzer consists of a source of highly focused X-ray beams that strike the sample, like a crystalline solid.

These X-rays diffract, producing an interference pattern that is recorded by an electronic detector.

Early insights into the DNA double-helical structure were obtained using XRD, which shows the X-shaped diffraction pattern and other dimensional details of the DNA helix.

Single-crystal XRD is used in protein crystallography to determine its three-dimensional structure.

In powder XRD, a polycrystalline sample is seen as concentric rings. The phase and purity of the material can be determined by comparison with the database.