Preparation of cryocooled protein crystal is provided by use of helium pressurizing and cryocooling to obtain cryocooled protein crystal allowing collection of high resolution data and by heavier noble gas (krypton or xenon) binding followed by helium pressurizing and cryocooling to obtain cryocooled protein crystal for collection of high resolution data and SAD phasing simultaneously. The helium pressurizing is carried out on crystal coated to prevent dehydration or on crystal grown in aqueous solution in a capillary.
This invention was made with U.S. Government support under National Institutes of Health Grant No. RR 01646, under National Science Foundation and National Institutes of Health (National Institute of General Medical Sciences) Grant No. DMR-0225180, National Institutes of Health Grant No. GM074899, and U.S. Department of Energy Grant No. DEFG02-97ER62443. The U.S. Government has certain rights in the invention.