How to do immunostaining (immunohistochemistry, IHC)?
The principle of immunohistochemical staining is, by taking advantage of antigen-antibody specific interaction, to identify the presence of a specific protein (its abundance and location) in the tissue by using a known antibody. The known antibody can be labeled beforehand or can be further reacted by second antibody which can by visualized with the help of different markers. Mostly the procedure consists of three steps: first, a primary antibody is added to a sample to bind to a specific protein; secondly an enzyme-conjugated secondary antibody is added to the sample to bind to the first antibody; thirdly, a chromogen substrate is added to the sample, color will deposit where the complexes of the specific protein-1st Ab-2nd AB-enzyme locate. immunostain technique is now widely used for the presence of a specific protein in situ. The specific procedures for frozen or paraffin sections please go to
IHC for frozen section or
IHC for paraffin section pages.