Welcome to I23

The long-wavelength macromolecular crystallography beamline I23 will be a unique facility for solving the crystallographic phase problem, using the small anomalous signals from sulphur or phosphorous which are present in native protein or RNA/DNA crystals. This will be of increased importance for projects where protein labelling to introduce anomalous scatterers is not feasible. In addition, the beamline's wavelength range will provide access to the M-edges of elements, with huge anomalous signals offering new opportunities for phasing large molecular complexes.

I23 will complement the existing suite of five MX beamlines at Diamond and will be optimised for operation in the wavelength range from 1.5 to 4 Å. The experimental end station will be in vacuum to minimize absorption and scattering effects. A large semi-cylindrical detector will allow measurements of a large range of diffraction angles and a multi-axis goniometer will be available for crystal alignment and orientation. An X-ray tomography setup will be integrated into the beamline end station to obtain the crystal shape and volume as a basis of an analytical absorption correction.