A SIMPLE DEVICE FOR STUDYING MACROMOLECULAR CRYSTALS UNDER MODERATE GAS-PRESSURES (0.1-10 MPA)

A simple device for studying crystalline samples under moderate gas pr essure (0.1-10 MPa) has been developed. The device employs a modified Cajon ultra-torr fitting to ensure a gas-tight seal around an X-ray ca pillary. The cell accommodates standard X-ray capillaries that require no modification. The device is straightforward to utilize and samples can be mounted with routine techniques and pressurized in a matter of seconds. In a subsequent development, a complete purging and pressuri zation system has been designed and constructed for use on beamline 7- 1 at the Stanford Synchrotron Radiation Laboratory. This paper describ es the construction of both the pressure cell and the delivery system and presents results of the use of this cell for the preparation of xe non derivatives to be used in phase determination by the multiple isom orphous replacement method.