[Histonet] Chromium trioxide

[Cheryl Crowder]

You can use periodic acid to oxidize your tissues as you would for the PAMS 
stain.  However, this is not the optimal solution when staining fungi.   5% 
chromium trioxide used for the GMS can be reused.  Since you are doing the 
stains manually, as many of us do, this works particularly well.  The fresh 
chromium trioxide is a clear orange color.  It can be reused until the color 
turns more brown in color.  This indicates that the oxidizing potential has 
been depleted.  You can also use 3% chromium trioxide instead of the 5% and 
heat the solution to 55 degrees and oxidize for 30 minutes.  Finally you can 
use 2% chromic acid in the microwave oven at 70% power for 45 seconds 
(solution should be about 55 degrees).  By using milder solutions or reusing 
your solution you will save money and time.
Cheryl