Dear Anita You are seeing the effects of a very modest reduction of vapor pressure of water with polymers. You could add salt to your reservoir and you could insure your drops are at the same temperature as your reservoir - not easy in conventional "constant temp" incubators.
George Sent via BlackBerry by AT&T -----Original Message----- From: anita p <crystals...@gmail.com> Sender: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> Date: Fri, 9 Sep 2011 19:22:53 To: <CCP4BB@JISCMAIL.AC.UK> Reply-To: anita p <crystals...@gmail.com> Subject: [ccp4bb] drops swelling Dear Crystallographers, I have set hanging drop trays with 2ul of protein and 2 ul of resorvior solution. I have seen in some cases the drops are swelling. My protein buffer has 15% glycerol in it. This is happening mainly when I have peg 400 or peg MME or MPD or Jeffamine in the buffer condition. Could any one suggest a remedy for this. with regards Anita