Diagnosis:
Nonspecific Background Staining in Immunohistochemistry
• All of these factors can cause nonspecific or background staining. Nonspecific protein-protein interactions between antibody and substrate can be reduced by the use of a “protein block” step.
• Sections should not be too thick, and drying during staining should be avoided by the use of a humidity chamber, and by controlling ambient humidity—the latter is an issue with some autostainers. This problem may be accentuated in winter when dry heat is used.
• The lowest antibody concentration, which produces reproducible results, should be used even when there appears to be no background at higher concentrations.
Taylor CR, Shi S-R, Barr NJ, Wu N: “Techniques of immunohistochemistry: principles, pitfalls, and standardization.”In: Dabbs DJ (ed.): Diagnostic Immunohistochemistry. New York: Churchill Livingstone, 2002, pp 3-44.
