Dear crystallographers, I am trying to crystallize a soluble protein which tends to form aggregates. The crystallization condition is 20% PEG 3350 + 0,2 M Na-Formate. During the crstallization process a thick skin is formed on top of the sitting-drops. As well the crystals are buried in precipitate. Before I start harvesting I try to remove the skin but still it is hardly possible to get any crystals out of these drops.
Any suggestions how to avoid the formation of skin on crystallization drops ? Cheers, Ulrike