What blocking buffer should I use for my western blotting experiment?

When choosing a blocking buffer for western blotting, there are several considerations. One consideration is to use a blocking buffer derived from the same species as the secondary antibody to prevent it from binding to the blocking agent instead of the target protein. Another consideration is to  ensure the blocking buffer won't interfere with the detection method, which can be done by carrying a test beforehand. Commonly used blocking buffers include 5% bovine serum albumin (BSA) and non-fat dry milk, as they are inexpensive and widely accessible for blocking solutions. Additionally, using single-protein blocking buffers, (e.g. casein) reduces the likelihood of cross-reactions with other components in the assay compared to using serum or milk solutions. These buffers are particularly useful when the goal is to prevent the blocking agent from interfering with antigen-antibody binding.