The Paragon stain evidently survived as a research tool. Its earlier history 
is, shall we say, more colorful.

The cryostat was introduced about forty years ago for cutting frozen 
sections, and replaced an older technology that involved cutting floating 
sections and staining them with whatever blue dye was handy (I even saw blue 
fountain pen ink used.) The Paragon stain was probably the best of the lot.

The old pathologists wouldn't change. My father never used a cryostat in his 
life, and neither did his younger associate. The one I got for them wound up 
being used as an ice cream freezer! 

I always refused to learn the old "wet knife" technique - sections were about 
12 mcm thick, folded, and densely stained. But the real problem I didn't want 
to deal with was that those old guys called everything cancer on those 
primitive frozen sections, and I had been taught in residency not to call 
things cancer that weren't cancer. Few pathologists of my generation (I'm 60) 
learned the old technique, though we were always under pressure to. The 
younger guys have never heard of it, and a good thing it is.

Bob Richmond
Samurai Pathologist
Knoxville TN