The ADDit™ Additives Screen contains 96 different small molecule and salt
solutions that have been found to be effective in aiding the crystallization of
biological macromolecules. It comprise a range of crystal growth promoters and
nucleation suppressants including detergents, chelators, reducing agents,
volatile and non-volatile organics, heavy atoms and salts. The purpose of these
solutions is to increase the quality and/or size of intitial crystal hits when
added to a lead condition. The additives are delivered in a 96well block
containing 1 ml of solution in each well at 10x the recommended final
concentration. The block is designed for easy use with a single or multi-channel
pipette, the latter allowing for rapid setup of a full 96 formulation
optimization screen. Furthermore, the additives are organized in the block
according to category in order to facilitate the setup of subsequent refinement
screens that lack some of the additive classes.