Re: aliquoting 4% formaldehyde

Posted by Alison J. North on
URL: http://confocal-microscopy-list.275.s1.nabble.com/aliquoting-4-formaldehyde-tp7585663p7585671.html

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Hi Doug,

For EM I always made up fresh formaldehyde from PFA powder and used it immediately.  However, for light microscopy on tissue culture cells we typically use frozen aliquots stored at -20.  I guess the question partly depends on the level of resolution you are going to achieve - it's possible that something like STORM might reveal ultrastructural changes caused by using frozen vs. fresh formaldehyde, but on a regular microscope I've never noticed it.  Choosing the correct buffer is more of an issue, people can be very sloppy about that.

Best,

Alison

On 9/20/2016 10:34 AM, Cromey, Douglas W - (dcromey) wrote:

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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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