Dear All, Is there any protocol for preparing a sample from (cleaning/dissolving) protein crystals for verifying their mass through mass spectrometry or SDS-PAGE? How many protein crystals are required? Should they all be from the same well, or can they be from different wells with slight changes in protein concentration/precipitant concentration/ pH? Should the crystals be cleaned with the reservoir solution and then dissolved in the protein buffer?
I am getting very thin, needle-like crystals which are too tiny for mounting. Adding Izit dye has also not been conclusive. Similar looking crystals have appeared in 3 conditions. Changing precipitant concentration, protein concentration, pH , and seeding have made no difference so far. I wish to determine whether the full protein is crystallizing, or only some fragment. The protein molecular weight is ~22KDa, and the crystals take ~3 weeks to grow. Thanks in advance, sreetama
