Dear Chris, I have not used this particular condition, but as a rule of thumb I use "like with like", e.g. glycerol, ethylene glycol, PEG400 etc. with PEG conditions, and saltlike compounds (sucrose, xylitol, salts) for salt conditions. In your case I would try glucose or xylitol or just look what happens if you increase the ammonium phosphate concentration to say 2M without adding glycerol.
Good luck! Herman -----Original Message----- From: CCP4 bulletin board [mailto:[email protected]] On Behalf Of Chris Ulens Sent: Thursday, May 26, 2011 12:27 PM To: [email protected] Subject: Re: [ccp4bb] recommendation for ammonium dihydrogen phosphate cryo Hi, I would like to get recommendations for a proper cryo solution for a crystallization hit from the Hampton crystal screen Ammonium di- hydrogen phosphate 0.4M. I tried increasing glycerol up to 30% with the same ammonium phosphate concentration or increasing glycerol up to 30% in the presence of 1.3M ammonium phosphate. Both gave iced up drops (I only tried quick and dirty tests by dipping a cover glass in liquid nitrogen). Thank you. -Chris
