 |
 |
Shivesh, You also might be precipitating out a contaminant, aggregate, isoform, etc., and its removal from the solution allows crystallization of the other. Lisa -----Original Message----- From: CCP4 bulletin board on behalf of Rob Gruninger Sent: Thu 8/23/2007 10:30 AM To: [log in to unmask] Subject: Re: [ccp4bb] crystal with precipitation Hi Shivesh I had something like this recently and found that changing the pH stopped the precipitation and the size of the crystals improved. If the crystals are large enough even if there is ppt present I would still try and collect data on them. This is likely not the case for you or you wouldn't be writing in:) hope this helps Rob > Dear all > I am trying to crystallize a 7kDa protein using MPD as a precipitant at > 16C.I have got small florets at 55-65% of MPD in 3-4 days.The problem is > that the drop is precipitating in one day only and the crystals are coming > with precipitation.I have added 5% glycerol and 100mM of Nacl as an > additive > with the mother liquor to avoid precipitation.But,the precipitation is > still > there.The volume of the mother liquor is 500 microlt.The drop size is > 2+2.I > welcome all the suggestions regarding avoiding the precipitation.Thanx is > advance. > Shivesh kumar > -- Robert J.Gruninger B.Sc. PhD Student Department of Chemistry & Biochemistry University of Lethbridge, 4401 University Dr. Lethbridge, AB, Canada, T1K 3M4 Phone:(403)329-2746 Fax:(403)329-2057