4/3/97
Can anyone please comment on the storage properties of common EM/LM fixatives.
We have some older 1% glut/4% formaldehyde in PO4 buffer. Is there some rule
of thumb that people are using, should we analyze before use, are there some
references we can access?
Thank you in advance for your comments.
Regards,
Ken Baker
bakerk@aa.wl.com
at lower pH so is accelerated when you buffer the solution to pH7. Our rule
is to buffer the fixative just before we use it and discard any buffered
fixative older than a week.
Mel Dickson
M.Dickson@unsw.edu.au
After exhaustive investigation some years ago, we arrived at the
following answer:
The highest grade glutaraldehyde or paraformaldehyde (distilled and
stored in glass vials under inert gas) will deterioate to approximately
one half their strengths in 3 weeks assuming they are in a buffer,
approximately at pH 7.4, and under continuous refrigeration. Therefore we
never keep fixatives for more than one week. We make them up the day of,
or the day before we use them.
Consider how valuable your sample is and how perfect it is expected to
look. A sample which has undergone autolysis will not benefit by
ultra-fresh fixation fluids, but living cells in culture will.
Oxygen and heat are deleterious to aldehydes. Glutaraldehyde in a mostly
empty bottle will not last very long, while glut in a glass vial sealed
under inert gas will last many years.
Hope this helps.
HILDEGARD CROWLEY
hcrowley@odin.cair.du.edu
this is effective but it seems like a reasonable thing to do. Seems as
though I came upon this in one of the early editions of Hyats general EM
techniques book.
*******************************************************
G.W. Erdos, Ph.D. Phone: 352-392-1295
Scientific Director,
ICBR Electron Microscopy Core Lab
218 Carr Hall Fax: 352-846-0251
University of Florida E-mail: gwe@biotech.ufl.edu
Gainesville, FL 32611 http://www.biotech.ufl.edu/~emcl/