Anti-Osteopontin has been tested for western blotting, immunohistochemistry (formalin-fixed paraffin-embedded sections) and ELISA. The antibody exclusively recognizes C-terminal fragments of both thrombin and MMP-cleaved OPN. The antibody recognizes the full-length osteopontin protein (which runs at 66 kDa on westerns), and 32 kDa for the MMP-cleaved C-fragment, but the 40 kDa N-terminal fragment is not recognized. A 1:1000 dilution will detect strongly approximately 250 ng of OPN protein on a blot. A 1:100-1:300 dilution used for IHC on human breast tumor tissues. No pretreatment is required for IHC when formalin-fixed paraffin-embedded tissue is stained. Specific conditions for reactivity and signal detection should be optimized by the end user.