| Precipitant Synergy uses synergistic combinations of mechanistically distinct precipitating agents to obtain crystallization hits from a primary set of 64 formulations. Each Precipitant Synergy (PS) formulation contains a carefully selected combination of at least two distinct precipitating agents including: (i) salts that affect the activity coefficient of water at high concentrations; (ii) organic solvents which alter the dielectric constant of the solvating medium; and (iii)PEGs which operate by increasing molecular crowding. Tests with 10 different proteins showed that the Precipitant Synergy screen roughly triples the number of different crystals obtained compared to other screens (Majeed, S., Ofek, Gl, Balachew, A., Huang, C.C., Zhou, Tl, Kwong, P.D. (2003) Structure, 11:1-20]. Patent Pending |