if you are crystallizing membrane protein here is a useful protocol from JCIPMT website follow the link http://jcimpt.scripps.edu/protocols/JCIMPT_PreparationofCHSStock.pdf
in my experience even after extensive sonication i filter the buffers otherwise we found that cholestrol comes out of solution when concentrating the protein at a later stage. padayatti On Mon, Apr 19, 2010 at 10:39 PM, Jerry McCully <[email protected]> wrote: > Dear ALL: > > Sorry for this kind of off-topic question. > > I am going to co-crystallize one protein with cholesterol. I read some > papers saying that > their protein can be pre-incubated with 1mM cholesterol in the presence of > 5% (v/v) ethanol. > > TO do so, I first dissolved cholesterol in 100% ethanol at a > concentration of 10mM. However, it is very difficult to make the dilution > into 5% ethanol either just in water or some buffers. > > Does anyone have such experience to make cholesterol solution in normal > buffers plus some ethanol? > > Thanks a lot, > > Jerry McCully > > ________________________________ > The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with > Hotmail. Get busy. -- Pius S Padayatti Scientist, Polgenix, Inc. 11000 Cedar Ave, Suite 260 Cleveland, OH 44106 Phone: 216-658-4528 Fax: 216-658-4529
