Device and method for screening crystallization conditions in solution crystal growth

An apparatus for determining optimum protein crystal growth conditions and for growing protein crystals in either 1 g or microgravity environments, said apparatus comprising:

• (a) a tray having an upper and lower surface, said tray defining at least one pair of first and second vertically disposed chambers therein for containing first and second crystallization solutions, respectively, said chambers having first and second openings through said upper surface to the exterior of said tray, respectively, and first and second orifices through said lower surface to the exterior of said tray, respectively;
• (b) said tray further defining a channel in said lower surface and in communication with said first and second orifices for containing a predetermined quantity of gelling substance which limits the rate of diffusive mixing of said first and second crystallization solutions so that said solutions are diffusively mixed over a predetermined period of time sufficient to achieve equilibration and to substantially reduce density driven convection disturbances therein;
• and
• (c) first and second closure means detachably connected to said tray for closing said first and second openings, respectively, said first closure means including crystal growth means in communication with said first chamber for containing a preselected quantity of protein solution in which protein crystals are grown of sufficient size and quality to withstand crystal structural analysis using x-ray diffraction techniques, said protein solution exposed to said first crystallization solution in said first chamber wherein the solubility of said protein solution is reduced at a rate responsive to said rate of diffusive mixing of said first and second crystallization solutions thus providing a controlled approach to critical supersaturation, said controlled approach allowing for screening of crystal growth conditions at preselected intervals during said period of time and substantially reducing density driven convection therein.

A disposable device for growing easily accessable protein crystals of sufficient size and quality to withstand crystal structural analysis using x-ray diffraction techniques, said disposable device comprising:

• (a) a tray having an upper and lower surface, said tray defining first and second vertically disposed chambers therein for containing a protein solution and precipitant solution, respectively, said chambers having first and second openings through said upper surface to the exterior of said tray, respectively, and first and second orifices through said lower surface to the exterior of said tray, respectively, said first chamber further having a conically shaped portion adjacent said first orifice;
• (b) said tray further defining a channel in said lower surface and in communication with said first and second orifices for containing a predetermined quantity of gelling substance which limits the rate of diffusive mixing of said protein solution and said precipitant solution and substantially reduces solutal convection therein so that said solutions are diffusively mixed over a predetermined period of time defined by said predetermined quantity of gelling substance sufficient to controllably reduce the solubility of said protein solution within said gelling substance to the point of critical supersaturation whereby said protein crystals are grown in said gelling substance in said channel;
• and
• (c) closure means detachably connected to said upper surface of said tray for sealingly closing said first and second openings.

A method for growing easily accessible protein crystals in a gel media of sufficient size and quality to withstand crystal structural analysis using x-ray diffraction techniques, said method comprising the steps of:

• (a) placing a precipitant solution and a protein solution into separate vertically disposed chambers defined in a housing having upper and lower surfaces;
• (b) providing fluid communication between said chambers through a channel defined in said lower surface of said housing;
• and
• (c) limiting the rate of diffusive mixing of said solutions through a preselected gelling substance contained in said channel by injecting said gelling substance into said channel prior to placing said precipitant solution and said protein solution into said chambers and allowing said gelling substance to gel, said diffusive mixing occurring over a period of time defined by the quantity of said gelling substance, said period of time sufficient to controllably reduce the solubility of said protein solution to the point of supersaturation whereby protein crystals are grown in said gelling substance in said channel.