Immunohistochemistry is a laboratory technique used to detect specific proteins in tissue samples by using antibodies that bind to those proteins. These antibody-protein interactions are visualized using a colorimetric or fluorescent label, allowing pathologists to see where and how much of a protein is expressed within a tissue. IHC is widely used in cancer diagnostics to classify tumor types, determine biomarker status (such as HER2 or PD-L1), and guide treatment decisions.
Sources
Immunohistochemistry. Cleveland Clinic. https://my.clevelandclinic.org/health/diagnostics/25090-immunohistochemistry
An Introduction to the Performance of Immunohistochemistry. Methods Mol Biol. https://pmc.ncbi.nlm.nih.gov/articles/PMC6749998/