USING SAMPLING TECHNIQUES IN PROTEIN CRYSTALLIZATION

The crystallization of homogeneous or highly purified macromolecules d epends on many variables such as precipitant, pH, choice of buffer, pr otein concentration, temperature, the participation of different mono- and divalent ions, as well as the presence of minute amounts of deter gent and organic molecules. Finding the best combination among these m any parameters is a multivariable optimization problem. This kind of p roblem can be treated mathematically by sampling techniques. We have u sed this technique for protein crystallization. The iterative procedur e starts with random sampling, followed by quantitative evaluation and cycles with weighted sampling. A simple procedure, derived from this concept and called MON48, has been successfully applied to many protei n crystallization problems.