A new class of blocking solutions based on chemically modified and fragmented ultra-pure casein. Effectively reduces unwanted binding of primary antibody and conjugates you use to charged surface of the slide and tissue section. Greatly reduces non-specific binding while preserving the specific reaction, by saturating potential non-specific protein-protein interactions. Moreover, in contrast to BSA-based, IgGm casein or serum-based blocking solutions there is no interaction of specific antibody and blocking protein itself. This is not comparable to other commercially available or home-made blocking solutions. Recommended for research and diagnostic pathology, especially for retrieved sections and polyclonal antibodies.