אימונוציטוכימיה ואימונוהיסטוכימיה

Immunocytochemistry or ICC and immunohistochemistry or IHC are staining techniques that use enzyme-linked antibodies to visualize and quantify specific proteins or antigens in cultured cells or tissue sections.

In ICC, a single layer of targeted cells is grown on a glass coverslip. The cells are fixed with a cross-linking agent to prevent enzymatic degradation of the antigen, then treated with a detergent to make the cell membrane permeable.

In IHC the whole tissue is fixed and embedded in a block of paraffin.Then, the sample is sectioned into thin slices, which can be placed on slides. Finally, the paraffin is removed to retrieve the antigen.

Once the antigens are accessible in the sample, they are bound by target-specific primary antibodies linked with conjugate enzymes like horseradish peroxidase.

The enzyme catalyzes the oxidation of DAB stain to a brown precipitate allowing visualization of the protein of interest.

If the signal detected is weak, secondary antibodies with conjugate enzymes are used to bind an unlabeled primary antibody on the target protein for further signal amplification.