Hi Mary,
not sure if you received this suggestion already.
Despite the low resolution diffraction 4-5 A as you report, try mounting
smaller crystals and see how well they perform. Very often our crystals
had a better freezing experience when they were small, even if
sufficient cryo protectant was present.
Another thing to try is once you have mounted a crystal, how does it
behave after flash annealing / wet annealing / multiple rounds of
annealing ?
Juergen
--
Jürgen Bosch
University of Washington
Dept. of Biochemistry, K-426
1705 NE Pacific Street
Seattle, WA 98195
Box 357742
Phone: +1-206-616-4510
FAX: +1-206-685-7002