Forms interface to calculate the expected signal in a MAD diffraction experiment.

The signal expected from a MAD experiment can be calculated using an approximation similar to the Crick & Magdoff equation for an MIR experiment. The form below uses this technique to estimate the signal available from a given MAD experiment. Hitting the "submit request" button will generate both pessimistic and optimistic estimates for the MAD signal available for your case.

Title for plot

Number of anomalous scatterers per asymmetric unit
Number of protein residues per asymmetric unit
Number of nucleic acid residues per asymmetric unit
Use library values Fe Se Pt U Yb
Other (generic absorption edge): K-edge L-edge M-edge
Use experimental values Min f' Max f' Max f"


Ideally the program should have a library of experimental results giving the achievable f' and f" terms for each element. I don't have a complete library ready yet, however, so for most elements you can only specify whether it is a K-edge experiment (delta f' =8, delta f'' =10) or an L-edge experiment (delta f' =13, delta f'' =40).

Last changed: 30-Mar-2009
back to X-ray Anomalous Scattering
Ethan A Merritt ©1996-2009/ / Biomolecular Structure Center at UW