Hi, Temperature is one obvious factor that comes to mind.
If you have access to MS, you could check the protein from the crystallization drops - find out if there's something 'chemical' going on such as proteolysis, modification of some sort, etc. - this has happened to me once before, the protein was undergoing very slow proteolysis, causing the resulting fragment to crystallize. In the absence of MS access you could check by SDSPAGE but not all modifications will show. Likewise, check the pH of the solution in the reservoir of the drops that gae you crystals (if you have a microelectrode, you can try checking the drop as well). Sometimes it gradually changes (e.g. MES buffers exposed to light, acetate buffers leaking acetic acid through the plastic) which can cause your final pH to be way off what you think it is. Likewise with salinity (conductivity). Finally, did you try seeding? If seeding does not work then you should take a really close look at the above :) Good luck! Artem > hi all, > I am working on a protein for which we get nicely diffracting > crystals but the problem is that the crystals grow from anywhere between > 4-6 months. Does anyone has any general suggestions as to what things > can be changed or tried to speed up the process. Any help or suggestions > would be welcome as i am crawling towards getting enough crystals to > make a synchroton visit:):) > > thanks > Neeraj > > -- > Neeraj Kapoor > TPCB Graduate Fellow > Sakmar Lab/ Molecular Biology & Biochemistry > The Rockefeller University > 1230 York Avenue, RRB 510 > New York, NY 10021 > lab.1.212.327.8284:fax.7904 > mobile: 917.535.2030 > http://www.rockefeller.edu/labheads/sakmar/sakmar-lab.html >
