Hi everyone, I need an advice on some strange thing happening to one of the protein i am working on. I used to purify it and set up trays and get some needle shaped crystals and trying seeding and other methods to optimise them. But recently, it stopped giving crystals even small needles. I am still following the same protocol with same buffer stocks. And not just once but since last three times it is happening. The purified protein in gel filtration is perfectly fine eluting at same position with symmetrical distribution. However when i am setting up trays under previous conditions, i am not getting the crystals. Instead the drops are quite clear. So i increased the concentration of the protein also from 8 to 11mg/ml, but still the same. Infact i tried adding ligand also but again no crystals. So i would be really grateful if anyone can give a valuable suggestion regarding this problem !!
Thanks BR Monica
