[ccp4bb] How to replace 2.45M K/Na phosphate buffer - SUMMARY
Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 Date: Fri, 22 Jun 2007 14:42:00 +0200 From: [EMAIL PROTECTED] Subject: [ccp4bb] How to replace 2.45M K/Na phosphate buffer - 2 To: CCP4BB@JISCMAIL.AC.UK Sorry: forgotten the pH: the crystals grow between pH 6.5 and 6.7. Claudia Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 Date: Fri, 22 Jun 2007 14:15:47 +0200 From: [EMAIL PROTECTED] Subject: [ccp4bb] How to replace 2.45M K/Na phosphate buffer To: CCP4BB@JISCMAIL.AC.UK Dear list, I've crystals in a condition including 2,45 M K/Na phosphate buffer for the well condition, and 1 microl protein + 0.8 microl Na/K phosphate buffer + 0.25 microl 30% 1,6-hexanediol in the drop condition. These crystals dissolve in several cryoprotectant solutions and survive only in malonic acid, with which they give diffraction at 7-8 A. Among the several different possibilities, I'd like to try to optimize the crystals, and one possiblity among others would be to change the buffer. Any suggestions, please, about how to replace K/Na phosphate? At these concentrations it is acting as a buffer but also as a precipitant and I was wondering if anybody has experienced nice buffer-salt combinations that proved to be useful starting from a similar condition. Thanks a lot, Claudia Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 _ Make every IM count. Download Windows Live Messenger and join the i’m Initiative now. It’s free. http://im.live.com/messenger/im/home/?source=TAGWL_June07 _ Make every IM count. Download Windows Live Messenger and join the i’m Initiative now. It’s free. http://im.live.com/messenger/im/home/?source=TAGWL_June07 _ With Windows Live Hotmail, you can personalize your inbox with your favorite color. www.windowslive-hotmail.com/learnmore/personalize.html?locale=en-usocid=TXT_TAGLM_HMWL_reten_addcolor_0607
[ccp4bb] How to replace 2.45M K/Na phosphate buffer
Dear list, I've crystals in a condition including 2,45 M K/Na phosphate buffer for the well condition, and 1 microl protein + 0.8 microl Na/K phosphate buffer + 0.25 microl 30% 1,6-hexanediol in the drop condition. These crystals dissolve in several cryoprotectant solutions and survive only in malonic acid, with which they give diffraction at 7-8 A. Among the several different possibilities, I'd like to try to optimize the crystals, and one possiblity among others would be to change the buffer. Any suggestions, please, about how to replace K/Na phosphate? At these concentrations it is acting as a buffer but also as a precipitant and I was wondering if anybody has experienced nice buffer-salt combinations that proved to be useful starting from a similar condition. Thanks a lot, Claudia Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 _ Make every IM count. Download Windows Live Messenger and join the i’m Initiative now. It’s free. http://im.live.com/messenger/im/home/?source=TAGWL_June07
Re: [ccp4bb] How to replace 2.45M K/Na phosphate buffer - 2
Dear Claudia, These crystals dissolve in several cryoprotectant solutions and survive only in malonic acid, with which they give diffraction at 7-8 A. You do not mention what the room temperature diffraction is like. If you have not tested it already, you should do so - even without malonate, you might only get 7-8A diffraction. Assuming the room-temp diffraction is OK, you could just try increasing the concentration of phosphate buffer - high salt can also act as a cryoprotectant. James Dr. James Murray Biochemistry Building Department of Biological Sciences Imperial College London London, SW7 2AZ Tel: +44 (0)20 7594 5276 -Original Message- From: CCP4 bulletin board on behalf of Claudia Scotti Sent: Fri 22/06/2007 13:42 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] How to replace 2.45M K/Na phosphate buffer - 2 Sorry: forgotten the pH: the crystals grow between pH 6.5 and 6.7. Claudia Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 Date: Fri, 22 Jun 2007 14:15:47 +0200 From: [EMAIL PROTECTED] Subject: [ccp4bb] How to replace 2.45M K/Na phosphate buffer To: CCP4BB@JISCMAIL.AC.UK Dear list, I've crystals in a condition including 2,45 M K/Na phosphate buffer for the well condition, and 1 microl protein + 0.8 microl Na/K phosphate buffer + 0.25 microl 30% 1,6-hexanediol in the drop condition. These crystals dissolve in several cryoprotectant solutions and survive only in malonic acid, with which they give diffraction at 7-8 A. Among the several different possibilities, I'd like to try to optimize the crystals, and one possiblity among others would be to change the buffer. Any suggestions, please, about how to replace K/Na phosphate? At these concentrations it is acting as a buffer but also as a precipitant and I was wondering if anybody has experienced nice buffer-salt combinations that proved to be useful starting from a similar condition. Thanks a lot, Claudia Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 _ Make every IM count. Download Windows Live Messenger and join the i'm Initiative now. It's free. http://im.live.com/messenger/im/home/?source=TAGWL_June07 _ Make every IM count. Download Windows Live Messenger and join the i'm Initiative now. It's free. http://im.live.com/messenger/im/home/?source=TAGWL_June07
Re: [ccp4bb] How to replace 2.45M K/Na phosphate buffer - 2
at around 4 molar P-buffer freezes clean. Best wishes Kornelius On Fri, 22 Jun 2007 14:42:00 +0200 Claudia Scotti [EMAIL PROTECTED] wrote: Sorry: forgotten the pH: the crystals grow between pH 6.5 and 6.7. Claudia Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 Date: Fri, 22 Jun 2007 14:15:47 +0200 From: [EMAIL PROTECTED] Subject: [ccp4bb] How to replace 2.45M K/Na phosphate buffer To: CCP4BB@JISCMAIL.AC.UK Dear list, I've crystals in a condition including 2,45 M K/Na phosphate buffer for the well condition, and 1 microl protein + 0.8 microl Na/K phosphate buffer + 0.25 microl 30% 1,6-hexanediol in the drop condition. These crystals dissolve in several cryoprotectant solutions and survive only in malonic acid, with which they give diffraction at 7-8 A. Among the several different possibilities, I'd like to try to optimize the crystals, and one possiblity among others would be to change the buffer. Any suggestions, please, about how to replace K/Na phosphate? At these concentrations it is acting as a buffer but also as a precipitant and I was wondering if anybody has experienced nice buffer-salt combinations that proved to be useful starting from a similar condition. Thanks a lot, Claudia Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 _ Make every IM count. Download Windows Live Messenger and join the i’m Initiative now. It’s free. http://im.live.com/messenger/im/home/?source=TAGWL_June07 _ Make every IM count. Download Windows Live Messenger and join the i’m Initiative now. It’s free. http://im.live.com/messenger/im/home/?source=TAGWL_June07 -- Kornelius Zeth Max Planck Institute for Developmental Biology Dept. Protein Evolution Spemannstr. 35 72076 Tuebingen, Germany [EMAIL PROTECTED] Tel -49 7071 601 323 Fax -49 7071 601 349