What kind of strategy for initial screening of protein crystallization conditions do you recommend?

Screening Suites are organized using systematic approaches that sample a wide chemical space and allow users to efficiently identify crystallization trends.

Each Screening Suite is organized using one or more of the following three strategies:

• Grid: systematically evaluates two factors, such as a precipitant, in various concentrations at various pH values
• Sparse Matrix: typically maps a wide sector of the crystallization conditions universe using many different chemicals
• Ionic Sampling: uses the effect the ionic strength of a solution has on a macromolecule, i.e., affecting surface charges and therefore its solubility

If protein supply is not a problem we recommend simultaneously screening as many conditions as possible, keeping in mind that Screening Suites are indexed by precipitant to facilitate the identification of trends.

If protein supply is limited, we recommend using a multiple-step approach, starting with a Sparse Matrix screen and moving towards precipitant-dedicated screens (Grids and Ionic sampling). For more information on strategies of each Suite please refer to the relevant Screening Suite product page.