Goat Serum blocking reagent or NGS can be used as a blocking agent to treat plastic surfaces, membrane or tissue after they have been sensitized with primary antibody or antigen. It provides an alternative to bovine serum albumin (BSA) and non-fat dry milk. It is effective in reducing nonspecific binding of proteins to reaction surfaces, thereby maximizing signal-to-noise ratio. This blocking agent is recommended for use in immunoassays where the primary antibody was produced in goat, as a source of non-specific serum protein or on tissue for immunohistochemical applications.