Patent ID: 7416708

Claim:
An apparatus of producing a protein crystal, comprising: a dialysis cell for containing a protein crystal and a protein solution filled around the protein crystal, the dialysis cell comprising (i) a quartz thin plate for mounting the protein crystal, provided with a light reflecting thin film on a portion of a surface thereof, (ii) an inner vessel for containing the quartz thin plate therein, provided with a surface portion covered with a dialysis membrane and filled with the protein solution therein, and (iii) an outer vessel filled with the protein precipitating agent solution outside the dialysis membrane; a protein solution inflow source selector for controlling a concentration of the protein in the protein solution around the protein crystal, the selector being capable of repeatedly switching between a protein solution and a diluent source for introduction into the dialysis cell; a protein concentration measurement device for measuring a concentration of the protein solution around the protein crystal; a two-beam interferometer for observing interference fringes around the protein crystal; a precipitating agent concentration measurement device for measuring the concentration of the precipitating agent in the dialysis cell; a precipitating agent inflow concentration control element for controlling a concentration of the precipitating agent in the protein solution around the protein crystal, the control element adjusting the concentration of the precipitating agent for introduction into the dialysis cell, in response to concentration measurements from the precipitating agent concentration measurement device.