The crystallization screens contain wide range of buffers with pH range from 3.5 to 9.5, and variety of precipitating agents including organic or inorganic salts, (poly)alcohols. Currently we have 12 screens (96‑condition each) for different types of biologically important macromolecules like proteins, membrane proteins, RNA, protein/nucleic acid complexes.

After having obtained crystalline material in the initial screens, the conditions have to be optimized with automated or manual mode. The aim of the optimization is to obtain monocrystals of sufficient dimensions and quality for the X‑ray diffraction experiments. For the optimization/refinement of the initial crystals we change pH and concentrations of the components of the hits of the initial screens. In addition, commercial or homemade additive screens are used (see below). 

Additive Screen is a library of small molecules that can affect the solubility and crystallization of biological macromolecules, including both soluble and membrane proteins. These small molecules can be an- or cations, detergents, linkers or cofactors of proteins that modulate their conformation.The goal is to perturb and manipulate sample-sample and sample-solvent interactions to alter the solubility and crystallization of a sample. Additives can stabilize or engender conformity by specific interaction with the macromolecules. There are numerous reports of the use of additives to improve the quality and size of macromolecular crystals.