Figure 7.

Process flow sheet of the crystallization strategy for the nuclease. The protein sample is purified to homogeneity using a combination of chromatographic methods. The pure and homogenous protein is chemically modified in order to localize the side chains and loops. The resultant compact protein molecule is then screened against a variety of chemical environments using commercially available sparse matrix screens to determine the best condition for the self-assembly of the protein molecules into a crystalline lattice.