[Histonet] Fat stains on P/S.

[mtitford <@t> aol.com]

 Tam Melville asks about fat stains on paraffin sections. 
Some lipids do remain in paraffin sections although most are removed by the organic solvents used in processing. I do not think any "fat droplets" would survive paraffin processing. Compound lipids, like sphingomyelin do survive and can be demonstrated by Sudan black, but the whole thing is less than perfect. They stain a kind of grey color. McManus published a method in which you take P/S sections to 70% alcohol, stain in sat. Sudan black in 70% alcohol for 30  min to 3 hours at 60oC, rinse in 70% alcohol, and then counterstain and mount in aquous mounting medium. I don't have the reference, but it is on page 302 of the 1968 edition of "Handbook of histopathological techniques" by C.F.A. Culling. We do it occasionally when a resident says "D***, I should have done a F/S fat stain on this"
 
Michael Titford
Pathology
USA Mobile AL
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