Beamlines | SAD experiments at I04-1

 I04-1 wavelength will be fixed at the Bromine K edge (E = 13530 eV, λ = 0.9163 Å). At this wavelength, a strong anomalous signal can be measured for most commonly used heavy atom derivatives therefore for those elements, single anomalous diffraction (SAD) experiments are possible.

Chart

Estimated anomalous difference at 0.92Å resolution for common elements

* Assuming 1 fully occupied heavy atom site per 300 residues for all elements except Se (1/42 heavy atoms/residue) and using the formula:

ΔF/F=sqrt(Nanomalous/2)*2f''/avg(Fp)=sqrt(Nano/2)*2f''/sqrt(346Nresidues)=2f'' * sqrt(1/692) * sqrt(Nano/Nresid) derived from Smith, J., Curr. Opin. Struct. Biol. vol1, p1002