Hello Histonetters: I tried sending this on August 12 but didn't see it in the
 daily digests so will try again.

  Patrick Haley wrote asking about the pinacyanol eryrosinate stain. We use
 this stain for Mast cells in skin specimens. The stain is quick and easy to use.
  Dilute 5 ml of concentrated stain with 45 ml of 30% ethanol just before use.
  Bring the section to 95% alcohol, stain for 3 minutes in the dark (this is
  important as the stain fades very quickly in light). Wipe excess strain off
  the back and around the edges of the tissue. Clear by quickly dipping two or   three times in acetone/ xylene (half and half) and then xylene. 
  The downside is making the stain. VERY tedious!!! I'm at home and don't have
  the method here, but it's something like this. Make 100 ml of 1% aqueous
  solutions of pinacyanol and erythrosin B and let stand in the dark overnight.
  The next day add about 60 ml of the erythrosin to the pinacynaol and mix
  well. Now comes the fun part! With a glass rod put a drop of the mix on a
  piece of white filter paper. There will be precipitate with a purple ring
  around it.
  Continue adding the erythrosin in small amounts at first and finally drop
  by drop until a pink ring appears around the precipitate and go slowly at the
  end because if you over titrate it doesn't work. However, deciding when the
  colored ring  is actually pink is the hardest part of the whole operation.
  Fortunately I've not had a batch not work yet and have made it 5 or 6 times.
  When the titration is complete,filter out the precipitate. Discard the
  solute and dry the filter paper in a warm oven. After the filter paper is
  dry, cut the area with the precipitate in to strips and put them in a dark
  brown bottle with 200 ml of 100% ethanol.
  Stable for at least one year.
  Mast cells are purple in a blue background and quite easy to see. Our
  pathologist brought the method with, him, really likes it, and has politely
  refused our efforts to try something easier to make.

 Wayne Hohn
 kootenay Lake Regional Hosp
 Nelson, B.C.
 Canada




Get your FREE Email and Voicemail at Lycos Communications at
http://comm.lycos.com