Immunohistochemistry is extremely useful for exploring and visualizing specific substances present in cells, tissues, organs and individuals by utilizing diverse and specific molecular recognition mechanisms of the body called antigen-antibody reaction. 
There are several important points in this step, but the first of which is to obtain and use a "good primary antibody". It is possible to detect substances (antigens) to be searched clearly, easily, and with high reproducibility by using a good primary antibody. 
Secondly, we need to immobilize substances (antigens) present in cells and tissues by fixation. However, the task of fixation bridges between molecules or molecules within a molecule in proteins, nucleic acids, lipid molecules, and forms a state called polymer. It is also an important point of immunohistochemistry to make this contradictory phenomenon successfully compatible.
The third point is to visualize the antigen-antibody reaction. There are several visualization methods. It should be visible not only to look, but also specific, clearly judged.
It is important to make it possible to discriminate reliable immunohistochemical reaction while conscious of these points to prevent incorrect detection results and detection judgment.
　In this presentation, I will explain the principle and basis of immunohistochemistry centering on the above three points.