following the thread on oil red o:

Lately we have started experiencing atrocious precipitate on our oil red o
slides.  These are frozen sections of skeletal muscle, 8-9 microns thick,
stained with oil red o in propylene glycol method.

These are large, black crystalline deposits (look much like snowflakes) seen
overlaying the entire specimen.  It is happening with homemade oil red o
stain as well as with commercially prepared oil red o from newcomber supply.
We have tried filtering (multiple filtering of the same stain solution),
decreasing incubation times in the stain (3 hours down to half an hour), and
making up new stain with every run.  I am starting to think maybe it is
something funny in the Milwaukee tap water we rinse with that is binding and
causing the problem.  Have not yet tried rinsing slides in distilled water.

Any similar experiences and solutions are appreciated!

Susan Danielson, MS
Neuromuscular Pathology Lab Coordinator
Dept. Neurology, Medical College of Wisconsin