Hi. Does anyone have experience using solutions containing manganese as crystallization buffers (buffers, not screening well solutions)? The protein that I am working requires manganese for activity, and I have read reports of related proteins crystallizing in manganese buffers. I made a buffer containing 3 mM manganese, that initially had a black color then turned to deep purple, and later almost clear. After a few weeks, the buffer turned an orange color and contains dark manganese syrup on the bottom. Does anyone know how to prepare a manganese buffer that is stable enough to be used as a protein buffer for crystallization screens?
Thanks, Matt