Hi, It happened with me also, thought I had not the needles but the crystals. Temperature matters a lot in these situations, leave the trays unattended for long and also try with various concentration. Make it highest say 15 mg/ml and dilute serially to set with a range of concentrations. Sometime batch to batch slight change can give such situations. I would say it is a stochastic phenomenon.
Best Wishes On Mon, Jan 26, 2015 at 8:22 PM, Monica Mittal <[email protected]> wrote: > 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 >
