Protein crystal growth apparatus for microgravitiy

Apparatus for growing protein crystals under microgravity environment, comprising a hollow canister elongated along an axis of elongation from a bottom end to a top end, bottom closure means for closing said bottom end, top closure means for closing said top end, a plurality of protein growth assemblies disposed in stacked relationship one above the other in said canister intermediate said bottom closure means and said top closure means, each of said assemblies comprising a tray having a planar upper surface and a plurality of spaced apart growth chambers recessed below said surface, each of said growth chambers having an upstanding pedestal and an annular reservoir disposed about said pedestal for receiving precipitants, each pedestal having an upper end disposed below said upper surface, a well recessed beneath said upper end of each pedestal defining a protein crystal growth receptacle, a flexible membrane positionable on said upper surface overlying said growth chambers, a sealing plate disposed above said membrane, said sealing plate having an upper surface and a planar lower surface, a plurality of bumpers depending downwardly from said lower surface, there being one bumper corresponding to each growth chamber, each bumper being disposed on said plate for alignment with a respective upper end of each respective pedestal for abutting and forcing portions of said membrane against said upper end to seal said well when said lower surface of said plate abuts remaining portions of said membrane to sandwich said membrane into abutting relationship with said upper surface of said tray to seal said reservoirs, and means for selectively urging said sealing plates into abutment with the membrane associated with a respective tray.