Hematoxylin Counterstain, 500 ml, produces blue stained nuclei with crisp detail. This commonly utilized counterstain is based on Gill's formulation and is mercury free. As this is a progressive stain formula, the intensity of nuclear staining can be adjusted to achieve the most desirable results either manually or in an automated instrument. This counterstain provides excellent color contrast with most commonly used peroxidase and alkaline phosphatase substrates and is suitable for use with non-aqueous and aqueous mountants.