Patrick Paulusse at Pembroke General Hospital in Ontario, Canada writes

I am running an HPS stain as my routine stain on a Leica Autostainer.<< He 
has a trouble-shooting problem that I can't offer any advice about.

I didn't know that the HPS (hematoxylin-phloxine-saffron Masson trichrome) 
stain was still in use as a routine stain anywhere. The stain originated in 
Canada - in Montreal, I think - and was in use at Columbia University in NYC in 
the 1960's. It is used as a general oversight stain, instead of H & E - many 
pathologists favored this approach in the 1930's, including Chandler Foote at New 
York Hospital (Cornell University Medical Center) in NYC.

Saffron (not safranin) is a natural dye also used as a spice - it flavors 
paella, for instance. It's extremely expensive, and (unless it's come along 
recently) there is no synthetic substitute for it. (It's prepared from the flowers 
- specifically the pistils - of Crocus sativus and is grown in Spain and the 
Middle East - Penzey's offers a wide selection of saffrons.) For histologic 
use, the dye is extracted in alcohol - some methods specify prolonged boiling of 
the dye in alcohol, using a reflux condenser. 

Patrick Paulusse, would you bring us up to date on this interesting old 
technique?

Bob Richmond
Samurai Pathologist
Knoxville TN