This classic Harris hematoxylin is a modified formulation eliminating the need for frequent filtering. Contains no mercury. Traditionally used as a regressive stain, Harris produces rapid distinct nuclear staining with no affinity for mucin. For regressive staining protocols, use of a differentiating solution is recommended to achieve the final stain intensity. Harris may also be used in progressive staining as desired. Available for purchase in a 500 mL container or 1 gallon rectangular F-style container, designed for easy storage and dispensing.