On Tue, 17 Jul 2001, Henry, Charlene wrote:

> however we want a oven that has a circulating air flow inside. We are drying
> our slides for 30 minutes at 60°C, however sometimes they still have small
> beads of water on the slides and the paraffin does not appear to be melted.

This is what happens if you melt the wax before the slides 
have dried. Droplets of water (or little air bubbles derived
from water) also impair adhesion of sections to glass. Slides
should drain vertically until pretty well all the water 
between the ribbon and the glass has gone, and drying should
occur at a temperature well below the nominal melting point
of the wax. 60C is too hot. 40-45C is OK. If you want to melt 
the wax do this immediately before putting the slides, still 
hot, into xylene. Melting can sometimes improve adhesion, 
especially of sections with wrinkles, and it also reduces
the time needed to dissolve the wax.
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John A. Kiernan
Department of Anatomy & Cell Biology
The University of Western Ontario
London,  Canada   N6A 5C1
   kiernan@u