[Histonet] Dry paraformaldehyde vapor

[Kelly D Mcqueeney]

In order to avoid tritium contamination of screens, I have been fixing 
my slides with paraformaldehyde vapor. PF powder is placed in the bottom 
of a dessicator with slides. Air is removed from the dessicator and the 
air-tight chamber exposes the tissue to paraformaldehyde overnight. Has 
anyone used this method? I am having a hard time understanding why the 
powder alone is sufficient for fixation. Liquid fixative is not an 
option because the receptor/lingand complex is washed off. The protocol 
is vaguely outlined in Biotechiques 26:432-434; Liberatore, et. al. 1999.

Thanks for your input,
Kelly