Val Plex 1 is a cocktail of AP anti-mouse antibody conjugate and HRP anti-rabbit antibody conjugate suitable for the detection of mouse and rabbit primary antibodies, respectively, as part of an IHC double-stain procedure on the VALENT Automated Slide Staining Platform. Val Plex 1 is intended to be used in combination with Val DAB Chromogen Kit (VLT8008K) to produce a brown stain at the site of rabbit primary antibody binding, and Val Fast Red Chromogen Kit (VLT8019K) to produce a red stain at the site of mouse primary antibody binding. Val Plex 1 is prepared using a proprietary micro-polymer technology that provides a highly sensitive detection system, with minimal background staining. Val Plex 1 does not use biotin nor streptavidin, thus avoiding non-specific staining associated with endogenous biotin. Val Plex 1 is provided ready-to-use and is intended to be applied as defined by the staining protocols on the VALENT Automated Slide Staining Platform.