High Background from Insufficient Non-Specific Blocking (Immunohistochemistry (High Background))

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Accepted Answer

Diffuse background staining observed throughout tissue sections in IHC experiments, indicating inadequate blocking of non-specific antibody binding sites. Common causes: 1) Blocking incubation period too short (less than 1 hr) 2) Inappropriate blocking agent selection for secondary antibody species 3) Insufficient concentration of blocking serum (below 10% normal serum) 4) Blocking agent does not match secondary antibody host species Solutions: 1) Extend blocking incubation period to minimum 1 hr at room temperature 2) Use 10% normal serum from the same species as the secondary antibody 3) Consider changing blocking agent if current protocol remains ineffective 4) Ensure blocking serum matches secondary antibody host species