Hematoxylin is a naturally occurring stain extracted from the logwood tree. For use in staining, the hematoxylin is oxidized to hematein which combines with the mordant and is the active staining ingredient. The usual mordants are aluminum salts, which give a bluer stain, and iron salts, which give a blacker stain. Iron hematoxylin is commonly used to make permanently stained smears from parasitology fixatives. Iron hematoxylin staining uses two separate solutions. Solution # 1 is a 1% w/v alcoholic solution of hematoxylin (catalog # 6185A) and solution # 2 is an acidified solution of iron salts (catalog number 6188A). The two solutions are mixed just before use to make the staining solution. These items are manufactured in the United States by Medical Chemical Corp.