Chris Larsen clarsen at
Mon Sep 26 08:54:15 EST 1994

Thanks for the opinions, all. Here's a summary of what I received:

The data might be collected on a single crystal, at four or more wavelengths around the 
absoption of Se, and the success would depend on the stability of the crystal to these
repeated doses of energy.  Sometimes, the crystal is more stable when it's frozen.
If the protein had three to five met, the structure (Patterson) determination 
would be optimal, as each one could still be accurately resolved from the others. 

Compared to MIR methods, only the data collection is difficult.  You must measure the data extremely
precisely (Rsym <3%) with care to measure at the proper wavelengths (that 
don't shift during data collection) without corrections for radiation
damage, perhaps absorption, etc.  If you are serious about this, can make the crystals,
have funding, and are willing to go to a synchrotron, get a form for beam time at 
brookhaven from Ann Emrick at 


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