Matured 10% alcoholic hematoxylin
200 mL 95% ethanol
Combine above reagents. Atmospheric oxidation slowly generates hematein in this stock solution, which should be ready to use in ~2 mo. To accelerate the oxidation, add 50 mg of one of the following for each gram of hematoxylin:
This will oxidize ~1/4 of the dye precursor to hematein and allow the stock solution to be used immediately. (The atmosphere works slowly on the remaining hematoxylin.) This valuable stock solution should be kept in a screw-capped bottle in a dark or dimly lit place. It will serve you well for 20 yr if you inspect it from time to time and make up any loss of volume due to evaporation of the solvent.
