Re: Carbowax (Polyethylene Glycol) (Paul Klosen)


I hope I'm not THE world authority on carbowax sections ;o) and that there
are still people that I can learn from.

I know several researchers who use PEG sections quite routinely, but it's
true: PEG/carbowax needs some getting used to and you need to hang in for
some time.

If you start cutting your first PEG block in ideal conditions (dry and
neither too warm or too cold), you'll be hooked instantly. You'll get
ribbons as long and as perfect as you like. But unfortunately, dry
conditions don't stay forever, and if you have to cut under humid
conditions you'll get to know the dark side of carbowax. Then there is the
problem of keeping the sections on the slides, especially if you want to do
ICC. Prolonged drying of the slides will give you good sticking sections,
but will destroy almost all immunoreactivity. That's the other problem with
PEG, upon mounting your sections you end up with the equivalent of
"dewaxed" slides, which you cannot keep dry if you intend on doing ICC.

That I stayed with PEG may also be related to the fact that I work mostly
on brain, which is easy to handle in PEG. I found ways to deal with
pancreas and embryos, but this is really challenging material in PEG.

Thus again my conclusion: I like PEG, but you have to be aware of some
problems. Some things are easy to handle in PEG, and some are virtually


                         (o -) O
Paul Klosen, PhD
CNRS UMR 7518 Neurobiologie des Fonctions Rythmiques et Saisonnieres
Universite Louis Pasteur
12 rue de l'Universite
F-67000 Strasbourg, FRANCE
tel:    fax:

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