I also don't understand what you mean by "The crystal always sticks with AmSO4" and "the crystal was still surrounded by AmSO4".... Is there solid AmSO4 in the drop? Judging from the concentration you state, this can't be the case. Just loop up the crystal and freeze I would say, the MPD + PEG400 should be plenty high enough for good cryo.
Bert van den Berg University of Massachusetts Medical School -----Original Message----- From: CCP4 bulletin board on behalf of James Holton Sent: Fri 4/3/2009 1:36 PM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] How to loop up crystal from AmSO4. If you want to get rid of mother liquid around crystal, mount it in oil. Howerver, what is wrong with NH4SO4? If your crystal can tolerate near-saturated NH4SO4, it is a cryoprotectant all by itself. -James Holton MAD Scientist HanJie_HCT Tai wrote: > Hi, > > I have a protein-DNA complex grown in 30 -40% MPD/0.2M Ammonium > sulfate/5% PEG 400/ 0.1M Tris (8.5). > > I believe that 30%MPD above does not require any cryoprotectant but i > hv a problem to loop a crystal up. The crystal always sticks with AmSO4. > > I tried to add 2ul up to 6ul reservoir solution into the protein drop > (1+1 ul). Although AmSO4 was diluted, the crystal was still surrounded > by AmSO4. > > The loop size is 0.1 -0.2mm, the crystal is about 0.1 mm. > > I tried to grow crystal without AMSO4 or 0.1M AmSO4, but no crystals > was shown up. > > Any suggestion to loop up the crystal without any AMSO4 attached? > > Regards, > HCT (HanJie) > > > > ------------------------------------------------------------------------ > Rediscover Hotmail®: Get quick friend updates right in your inbox. > Check it out. > <http://windowslive.com/RediscoverHotmail?ocid=TXT_TAGLM_WL_HM_Rediscover_Updates1_042009>
