Deep Space Black™ (DSB) is a novel permanent chromogen that produces a dark grey to black stain in the presence of horseradish peroxidase (HRP). The kit consists of liquid Deep Space Black Chromogen and Buffer that are stable for 8 hours at room temperature once mixed. Deep Space BlackTM is clearly distinguishable from Warp Red™, DAB, Vina Green™ and Ferangi Blue™ on a single slide, enabling high flexibility for its application in Multiplex IHC™ and double stains. Deep Space Black is suitable for both immunohistochemistry (IHC) and in situ hybridization applications including HPV, CMV, EBV, Kappa, Lambda, p63, HMWCK, TTF-1, Ki-67, and other targets/antigens such as cytokeratins, melanoma, and basal and myoepithelial cells. The reaction product is insoluble in alcohols and xylene and, therefore, a variety of counterstains and permanent mounting media can be used with this chromogen kit.