Re: aliquoting 4% formaldehyde

Posted by Michelle Peckham on
URL: http://confocal-microscopy-list.275.s1.nabble.com/aliquoting-4-formaldehyde-tp7585663p7585668.html

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We also use frozen aliquots of frozen 4% paraformaldehyde, with no problems. Best to check how it was made – pH can be off for example -

 

From: Confocal Microscopy List <[hidden email]> on behalf of "MODEL, MICHAEL" <[hidden email]>
Reply-To: Confocal Microscopy List <[hidden email]>
Date: Tuesday, 20 September 2016 at 15:47
To: "[hidden email]" <[hidden email]>
Subject: Re: aliquoting 4% formaldehyde

 

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Hi Doug,

 

We, too, keep it frozen, that’s what many sources recommend to prevent formation of formic acid. But I haven’t seen much trouble when people keep it at room temperature. In any case, freezing cannot hurt, and the poor quality of your sample may have been due to something else. But even the freshest formaldehyde solution may cause cell shrinking, swelling or blebbing.

 

Mike Model

 

From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Cromey, Douglas W - (dcromey)
Sent: Tuesday, September 20, 2016 10:34 AM
To: [hidden email]
Subject: aliquoting 4% formaldehyde

 

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I was talking with a student yesterday about their cells which did not look particularly good under the microscope. The discussion eventually came around to fixation. The student told me that he made up some 4% formaldehyde fixative and then froze back (20 deg C) aliquots for later use. This was something he had seem on an online research forum. In my fairly lengthy experience I have never heard of this being done and I am suspicious that this is NOT a good idea. Thoughts?

 

Doug

 

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Douglas W. Cromey, M.S. - Associate Scientific Investigator

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