AdvanBlock-PF is a protein-free blocking solution, optimized for use with the WesternBright MCF fluorescent Western blotting kit and also an excellent blocking reagent for chemiluminescent Western blotting. It is fast-acting, and stabilizes the fluorescence of the WesternBright MCF secondary antibody conjugates. AdvanBlock-PF can reduce background when used with primary antibodies that have a high degree of cross-reactivity with protein blockers such as BSA, casein or milk protein. With low-quality primary antibodies that may require protein-based blocking agents, BSA or non-fat dry milk can be dissolved directly in the AdvanBlock-PF solution used to dilute the antibody. Provided as a 5X concentrate.