We have two crystal screens for membrane proteins in a format compatible with the Honeybee 963 robot: MemStart and MemSys.
The crystallisation of membrane proteins is a difficult area since the proteins themselves are often complex in structure and often detergents are used to extract the proteins from lipid environments. Careful handling and preparation are vital in this process. Different detergents have different mycell sizes that have an influence on the formation of crystals and can themselves crystallise! Recent experience has shown that the detergent DDM which is often used as the most "crystallisation friendly" detergent needs to be considered carefully during protein preparation. Ideally you do not want an excess of this detergent introduced into the crystallisation experiment, however below the CMC (@0.02%) mycelles will not form. The mycell size for DDM is XXX and therefore the use of 100kDa cut off concentrators should be ok, HOWEVER.