The invention discloses new substituted anthraquinone dyes that may be useful as cellular stains. In some aspect of the invention, the nuclear stains are useful for staining the nuclei of dead or fixed cells. Another aspect of the invention relates to substituted anthraquinone dyes comprising an enzyme substrate moiety that is transformable or cleavable by an enzyme such that the transformation or cleavage of the substrate moiety causes a detectable change in the functionality or spectral properties of the dye.