how to store fixing solution with (para)formaldehyde - (Dec/12/2005 )
Hi everybody,
I need your help! I have a solution for fixing my cells with 3.7% Formaldehyde and 4% Sucrose in 1x PBS. Normally I use it for around two month, storing the bottle cool. Now my colleque said that it is not necessary to do that and that it can be bad for fixing. The polimerisation to paraformaldehyde is not a problem and so I really think about what is the best temperature to store. What do you think? 
Thanks a lot for your help!
Have a nice christmas time!
Andrea
Well, I'm not a chemist but I always work with formaldehyde 4% and glucose 4% in 1X PBS. I prepare 100ml aliquotes and store them at room temperature up until one month, with good results all the time (I always fix for 30 minutes). I think concentration of formaldehyde is to low for transformation into paraformaldehyde, and contamination because of the glucose is not really likely, but don't have a clue what could storing could affect the fixation.
Good luck! 
I need your help! I have a solution for fixing my cells with 3.7% Formaldehyde and 4% Sucrose in 1x PBS. Normally I use it for around two month, storing the bottle cool. Now my colleque said that it is not necessary to do that and that it can be bad for fixing. The polimerisation to paraformaldehyde is not a problem and so I really think about what is the best temperature to store. What do you think?
Thanks a lot for your help!
Have a nice christmas time!
Andrea
I don't think the polymerization would matter at all. I have only fixed w/PFA both tissue and cells for years. Though I am sure somewhere out there someone will have an exception to what I said.
Hmm..it would be helpful to know what reasons your co-worker gave you that make you question your method of storage. As you say so far, it seems nothing is wrong.
At times I also believe in the phrase 'if it's not broken, don't fix it" meaning if everything working perfectly for you, just keep doing it. Take that w/a grain of salt however.