Edge Artifacts from Tissue Section Drying (Immunohistochemistry (High Background))

Question

Accepted Answer

Higher background staining concentrated at the edges of tissue sections compared to the center, indicating tissue dehydration during the staining procedure. Common causes: 1) Tissue sections exposed to air and allowed to dry out during procedure 2) Insufficient humidity in incubation environment 3) Reagents evaporating from tissue edges during incubation steps 4) Lack of hydrophobic barrier to retain reagents on tissue sections Solutions: 1) Keep tissue sections in a humidified chamber throughout the procedure 2) Use a hydrophobic barrier pen (e.g., ab2601, PAP pen) to retain reagents in place 3) Keep tissue sections covered with buffer at all times between incubations 4) Ensure adequate reagent volume to prevent evaporation from edges 5) Monitor tissue sections for signs of drying and add buffer immediately if needed