Francisco Javier H Blazquez
fjhblazq at FOX.CCE.USP.BR
Wed Oct 27 12:09:04 EST 1993
In article 656 at mnemosyne.cs.edu, anon1167 at nyx.cs.du.edu (M) wrote:
>I was recently told that, when using paraformaldehyde for
>perfusion, the P must be made immediately prior to perfusion.
In fact, when the paraformaldehyde powder is heated to 60 oC, a gas is
liberated from the polymerizated form. This gas is the formaldehyde which
dissolves in the hot water. Without the methanol as a stabilizer, the gas is
lost and the concentration drops.
We usually dissolve the paraformaldehyde in the alkaline form of the
Sorensen's phosphate buffer and this solutions is stored as a 20% stock
solution at 37% to prevent precipitation.
Small aliquots can then be taken and dissolved to a 4% solution in
the acid form of the phosphate buffer.
Some references about this subject may be mailed.
Francisco J. Hernandez-Blazquez.....Department of Histology
Instituto de Ciencias Biomedicas
Universidade de Sao Paulo
Av. Prof. Lineu prestes, 1524
05508-900 - Sao Paulo (Brazil)
INTERNET..........................fjhblazq at fox.cce.usp.br
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