RE: [Histonet] PFA preparation
I stopped making up paraformaldehyde from the powder; too toxic. Another colleague told me she buys it in a 16% solution, EM grade from EMS (10 x 10ml vials). I started using that, along with the glutaraldehyde to prepare my working solution. Peggy -Original Message- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Madary, Joseph Sent: Monday, March 21, 2011 11:27 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] PFA preparation Anyone have a decent method to prepare paraformaldehyde. I have the powder and the NOAH, hood, heat source but forgot the method. Nick Madary, HT/HTL(ASCP)QIHC Histology Mgr, Medimmune 301.398.6360(lab), 4745(vm),9745(fax) To the extent this electronic communication or any of its attachments contain information that is not in the public domain, such information is considered by MedImmune to be confidential and proprietary, and expected to be used only by the individual(s) for whom it is intended. If you have received this electronic communication in error, please reply to the sender advising of the error in transmission and delete the original message and any accompanying documents from your system immediately, without copying, reviewing or otherwise using them for any purpose. Thank you for your cooperation. To the extent this electronic communication or any of its attachments contain information that is not in the public domain, such information is considered by MedImmune to be confidential and proprietary. This communication is expected to be read and/or used only by the individual(s) for whom it is intended. If you have received this electronic communication in error, please reply to the sender advising of the error in transmission and delete the original message and any accompanying documents from your system immediately, without copying, reviewing or otherwise using them for any purpose. Thank you for your cooperation. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] PFA preparation
I concur with the others. For about 6 years I've made it from powder but the toxicity risk bothered me until I realized how safely and cheaply you can just buy the same stuff. We get a discount through our stockroom on a 4L bottle of 10% Buffered Formalin from Fisher (SF100-4) for $28. I started getting neutral buffered formalin instead from Fisher. --On Monday, March 21, 2011 11:25 AM -0500 Montina Van Meter montina.vanme...@pbrc.edu wrote: Nick, I too have tried to limit my exposure after making it from scratch for 30+ years. I currently purchase it from USB Corp. located in Cleveland Ohio. They have been acquired by Affymetrix and you will be directed to that website when you type in www.usbweb.com. Cat.# 19943 1LT Paraformaldehyde Solution, 4% in PBS, 1L $48.00 Regards, Tina Montina J. Van Meter Lab Manager Autonomic Neuroscience 225-763-2564 vanme...@pbrc.edu -Original Message- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Madary, Joseph Sent: Monday, March 21, 2011 10:27 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] PFA preparation Anyone have a decent method to prepare paraformaldehyde. I have the powder and the NOAH, hood, heat source but forgot the method. Nick Madary, HT/HTL(ASCP)QIHC Histology Mgr, Medimmune 301.398.6360(lab), 4745(vm),9745(fax) To the extent this electronic communication or any of its attachments contain information that is not in the public domain, such information is considered by MedImmune to be confidential and proprietary, and expected to be used only by the individual(s) for whom it is intended. If you have received this electronic communication in error, please reply to the sender advising of the error in transmission and delete the original message and any accompanying documents from your system immediately, without copying, reviewing or otherwise using them for any purpose. Thank you for your cooperation. To the extent this electronic communication or any of its attachments contain information that is not in the public domain, such information is considered by MedImmune to be confidential and proprietary. This communication is expected to be read and/or used only by the individual(s) for whom it is intended. If you have received this electronic communication in error, please reply to the sender advising of the error in transmission and delete the original message and any accompanying documents from your system immediately, without copying, reviewing or otherwise using them for any purpose. Thank you for your cooperation. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet Merced M Leiker Research Technician II 354 Biomedical Research Building School of Medicine and Biomedical Sciences State University of New York at Buffalo 3435 Main St, Buffalo, NY 14214 Ph: (716) 829-6033 Fx: (716) 829-2725 No trees were harmed in the sending of this email. However, many electrons were severely inconvenienced. ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] PFA preparation
We routinely add paraformaldehyde to alkaline water at room temperature while stirring and wait only about 30-60 mintues for it to dissolve. Then we add a concentrated amount of PBS up to the total required volume (so that the buffer is 1x in the final volume). Then we add acid to bring the pH back down to 7. Then we filter it since not all of the PFA has dissolved (though most of it has). Merced --On Monday, December 08, 2008 9:11 AM +1100 Tony Henwood [EMAIL PROTECTED] wrote: My experience is that when you add paraformaldehyde to water all it forms is a colloidal solution (ie on standing, the paraformaldehyde settles with very little going into solution (personal experience, waited one week, then gave up). Has your experience been different? Regards Tony Henwood JP, MSc, BAppSc, GradDipSysAnalys, CT(ASC) Laboratory Manager Senior Scientist Tel: 612 9845 3306 Fax: 612 9845 3318 the children's hospital at westmead Cnr Hawkesbury Road and Hainsworth Street, Westmead Locked Bag 4001, Westmead NSW 2145, AUSTRALIA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, 7 December 2008 7:30 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] PFA preparation Hi, So then what is the best way to prepare formaldehyde fixative from PFA? The way I have been taught, which differs from what I have read, is to dissolve 4% into ddH2O at room temperature. After that one could add PBS or buffer. I've also been taught that too much heat during preparation degrades PFA, and that PFA (or formaldehyde solution, rather) stored too long will lose freshness because it degrades. What I read is different. Texts suggest to dissolve the PFA in warm water, and that aging of the fix is due to repolymerization, not through degradation. What should i do? Eric Schmidt University of Calgary Medical Sciences ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet * This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message and any attachments are those of the individual sender, and are not necessarily the views of The Children's Hospital at Westmead This note also confirms that this email message has been virus scanned and although no computer viruses were detected, The Childrens Hospital at Westmead accepts no liability for any consequential damage resulting from email containing computer viruses. ** ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet Merced M Leiker Research Technician II 354 BRB (pkgs) / 140 Farber Hall (letters) School of Medicine and Biomedical Sciences State University of New York at Buffalo 3435 Main St, Buffalo, NY 14214 Ph: (716) 829-6033 Fx: (716) 829-2725 Without my flaws I'm really very boring. - random internet blog commentator ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] PFA preparation: Does dissolution also mean that the PFA has depolymerized?
Hi Merced, Thanks for your reply. So then you manipulate pH rather than temperature to ensure the dissolution of PFA. Does dissolution also mean that the PFA has depolymerized? Are you saying heating to 60 degrees C is not required, or that it is not recommended? I've been told that heating 'degrades' the PFA and one wants to avoid this. But according to other sources, the heating step is required to ensure that the PFA does in indeed degrade, degrade into formaldehyde. Eric University of Calgary Medical Sciences We routinely add paraformaldehyde to alkaline water at room temperature while stirring and wait only about 30-60 mintues for it to dissolve. Then we add a concentrated amount of PBS up to the total required volume (so that the buffer is 1x in the final volume). Then we add acid to bring the pH back down to 7. Then we filter it since not all of the PFA has dissolved (though most of it has). Merced --On Monday, December 08, 2008 9:11 AM +1100 Tony Henwood [EMAIL PROTECTED] wrote: My experience is that when you add paraformaldehyde to water all it forms is a colloidal solution (ie on standing, the paraformaldehyde settles with very little going into solution (personal experience, waited one week, then gave up). Has your experience been different? Regards Tony Henwood JP, MSc, BAppSc, GradDipSysAnalys, CT(ASC) Laboratory Manager Senior Scientist Tel: 612 9845 3306 Fax: 612 9845 3318 the children's hospital at westmead Cnr Hawkesbury Road and Hainsworth Street, Westmead Locked Bag 4001, Westmead NSW 2145, AUSTRALIA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, 7 December 2008 7:30 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] PFA preparation Hi, So then what is the best way to prepare formaldehyde fixative from PFA? The way I have been taught, which differs from what I have read, is to dissolve 4% into ddH2O at room temperature. After that one could add PBS or buffer. I've also been taught that too much heat during preparation degrades PFA, and that PFA (or formaldehyde solution, rather) stored too long will lose freshness because it degrades. What I read is different. Texts suggest to dissolve the PFA in warm water, and that aging of the fix is due to repolymerization, not through degradation. What should i do? Eric Schmidt University of Calgary Medical Sciences ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet * This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message and any attachments are those of the individual sender, and are not necessarily the views of The Children's Hospital at Westmead This note also confirms that this email message has been virus scanned and although no computer viruses were detected, The Childrens Hospital at Westmead accepts no liability for any consequential damage resulting from email containing computer viruses. ** ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet Merced M Leiker Research Technician II 354 BRB (pkgs) / 140 Farber Hall (letters) School of Medicine and Biomedical Sciences State University of New York at Buffalo 3435 Main St, Buffalo, NY 14214 Ph: (716) 829-6033 Fx: (716) 829-2725 Without my flaws I'm really very boring. - random internet blog commentator ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
Re: RE: [Histonet] PFA preparation
We routinely add PFA to 0.1M PBS and heat, stir the solution for 2-3 hours. Longer heating will result in acidic pH - depolymerizing..? Then we adjust the pH to 7.4 2008-12-09 tf 发件人： Merced Leiker 发送时间： 2008-12-09 00:05:52 收件人： Tony Henwood; [EMAIL PROTECTED]; histonet@lists.utsouthwestern.edu 抄送： 主题： RE: [Histonet] PFA preparation We routinely add paraformaldehyde to alkaline water at room temperature while stirring and wait only about 30-60 mintues for it to dissolve. Then we add a concentrated amount of PBS up to the total required volume (so that the buffer is 1x in the final volume). Then we add acid to bring the pH back down to 7. Then we filter it since not all of the PFA has dissolved (though most of it has). Merced --On Monday, December 08, 2008 9:11 AM +1100 Tony Henwood [EMAIL PROTECTED] wrote: My experience is that when you add paraformaldehyde to water all it forms is a colloidal solution (ie on standing, the paraformaldehyde settles with very little going into solution (personal experience, waited one week, then gave up). Has your experience been different? Regards Tony Henwood JP, MSc, BAppSc, GradDipSysAnalys, CT(ASC) Laboratory Manager Senior Scientist Tel: 612 9845 3306 Fax: 612 9845 3318 the children's hospital at westmead Cnr Hawkesbury Road and Hainsworth Street, Westmead Locked Bag 4001, Westmead NSW 2145, AUSTRALIA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, 7 December 2008 7:30 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] PFA preparation Hi, So then what is the best way to prepare formaldehyde fixative from PFA? The way I have been taught, which differs from what I have read, is to dissolve 4% into ddH2O at room temperature. After that one could add PBS or buffer. I've also been taught that too much heat during preparation degrades PFA, and that PFA (or formaldehyde solution, rather) stored too long will lose freshness because it degrades. What I read is different. Texts suggest to dissolve the PFA in warm water, and that aging of the fix is due to repolymerization, not through degradation. What should i do? Eric Schmidt University of Calgary Medical Sciences ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet * This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message and any attachments are those of the individual sender, and are not necessarily the views of The Children's Hospital at Westmead This note also confirms that this email message has been virus scanned and although no computer viruses were detected, The Childrens Hospital at Westmead accepts no liability for any consequential damage resulting from email containing computer viruses. ** ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet Merced M Leiker Research Technician II 354 BRB (pkgs) / 140 Farber Hall (letters) School of Medicine and Biomedical Sciences State University of New York at Buffalo 3435 Main St, Buffalo, NY 14214 Ph: (716) 829-6033 Fx: (716) 829-2725 Without my flaws I'm really very boring. - random internet blog commentator ___ Histonet mailing list Histonet@lists.utsouthwestern.edu ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
RE: [Histonet] PFA preparation
My experience is that when you add paraformaldehyde to water all it forms is a colloidal solution (ie on standing, the paraformaldehyde settles with very little going into solution (personal experience, waited one week, then gave up). Has your experience been different? Regards Tony Henwood JP, MSc, BAppSc, GradDipSysAnalys, CT(ASC) Laboratory Manager Senior Scientist Tel: 612 9845 3306 Fax: 612 9845 3318 the children's hospital at westmead Cnr Hawkesbury Road and Hainsworth Street, Westmead Locked Bag 4001, Westmead NSW 2145, AUSTRALIA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Sunday, 7 December 2008 7:30 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] PFA preparation Hi, So then what is the best way to prepare formaldehyde fixative from PFA? The way I have been taught, which differs from what I have read, is to dissolve 4% into ddH2O at room temperature. After that one could add PBS or buffer. I've also been taught that too much heat during preparation degrades PFA, and that PFA (or formaldehyde solution, rather) stored too long will lose freshness because it degrades. What I read is different. Texts suggest to dissolve the PFA in warm water, and that aging of the fix is due to repolymerization, not through degradation. What should i do? Eric Schmidt University of Calgary Medical Sciences ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet * This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message and any attachments are those of the individual sender, and are not necessarily the views of The Children's Hospital at Westmead This note also confirms that this email message has been virus scanned and although no computer viruses were detected, The Childrens Hospital at Westmead accepts no liability for any consequential damage resulting from email containing computer viruses. ** ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
Re: [Histonet] PFA preparation
You were taught correctly. And the socalled degradation is re-polymerization as you wrote. The only thing is that you should add buffer salts bettwen than PBS. René J. --- On Sat, 12/6/08, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: From: [EMAIL PROTECTED] [EMAIL PROTECTED] Subject: [Histonet] PFA preparation To: histonet@lists.utsouthwestern.edu Date: Saturday, December 6, 2008, 3:30 PM Hi, So then what is the best way to prepare formaldehyde fixative from PFA? The way I have been taught, which differs from what I have read, is to dissolve 4% into ddH2O at room temperature. After that one could add PBS or buffer. I've also been taught that too much heat during preparation degrades PFA, and that PFA (or formaldehyde solution, rather) stored too long will lose freshness because it degrades. What I read is different. Texts suggest to dissolve the PFA in warm water, and that aging of the fix is due to repolymerization, not through degradation. What should i do? Eric Schmidt University of Calgary Medical Sciences ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet ___ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet
