Welcome to I04-1

Please discuss your requirements with a member of the beamline team before your experiment.

I04-1's wavelength is fixed at the Bromine K edge (E = 13530 eV, λ = 0.9163 Å), where a strong anomalous signal can be measured for most commonly-used heavy atom derivatives (see figure).  SAD is usually very effective here - unsurprisingly: thanks to modern detectors and phasing algorithms, tunability is essential only for special cases, especially if the experiment is done carefully (see e.g. Krojer, Pike, von Delft, Acta D 2013)

Estimated anomalous difference at 0.92Å resolution for common elements.  These were calculated assuming:  for all elements, 1 fully occupied heavy atom site per 300 residues;  for Se, 1:42 heavy atoms:residue;  and using the formula derived from Smith, J., Curr. Opin. Struct. Biol. vol1, p1002 (1991).