Edge effect / uneven staining across the slide (Immunohistochemistry (IHC))

Question

Accepted Answer

Slide edges show darker staining than center, or one half stains more than the other; reproducibility between fields is poor. Common causes: 1) Incubation liquid did not cover the slide evenly 2) Slide dried out during incubation, causing uneven reagent distribution 3) Temperature or humidity was unstable 4) Incubation time was too long Solutions: 1) Keep the slide moist throughout — never let it dry 2) Use enough reagent volume to fully cover the tissue section 3) Use a humid chamber to maintain constant temperature and humidity 4) Shorten incubation time; standardize the procedure