This formulation provides incredible nuclear detail in routine H&E and immunoperoxidase procedures, as well as for some special stains. This hematoxylin requires virtually no filtering and produces minimum scum due to oxidation. It has been specially formulated to eliminate the necessity for differentiation, and staining time is 30 seconds to 5 minutes, depending upon the type of procedure it is used for. The addition of acetic acid to CAT Hematoxylin’s preparation is believed to increase the selectivity of the stain. The formula has also been designed to slow down the oxidation process, thus stabilizing the hematoxylin. There is no mercury used in the preparation of this product; glycerol has been added as a stabilizer to help prevent over-oxidation and rapid evaporation. (Modified Lillie-Mayer’s).