Blocking serum serves to prevent non-specific binding of antibodies or other biomolecules to surfaces, such as cell membranes or microtiter plates. By saturating unbound sites on these surfaces, blocking serum effectively reduces background noise and enhances the specificity of assays such as immunofluorescence, enzyme-linked immunosorbent assay (ELISA), or Western blotting. These reagents help ensure accurate and reliable results by minimizing false positives and maximizing signal-to-noise ratios.