What are the types of immunostaining methods?

There are several types of immunostaining methods. They are differentiated based on the immunostaining protocol. The three main types of immunostaining methods include Immunohistochemistry, Flow cytometry, and Immuno-electron microscopy (EM immunolabeling).

Immunohistochemistry 

Immunohistochemistry is the most widely-used immunostaining method. In this technique, a small sample and an antibody that is known to bind to the intended target are placed together on a glass slide. The sample and antibody are stained with enzymes or dyes, enabling the researcher to more clearly identify specific proteins and cells under a microscope. 

Immunohistochemistry is used to diagnose different types of cancer and to differentiate between blood disorders and neurological conditions. 

Flow cytometry

Flow cytometry involves using antibodies with colored labels to identify specific proteins that the technician is looking for. The cells are singled out, counted, and categorized one at a time by a laser. 

Flow cytometry is used to diagnose leukemia, autoimmune diseases, infectious diseases, and lymphoma. 

Immuno-electron microscopy (EM immunolabeling)

Immuno-electron microscopy involves the use of colloidal gold, which is easily visible under an electron microscope. In this process, when colloidal gold particles are attached to the antibodies, the antibody grabs on and holds on fast to the antigen. When viewed under an electron microscope, the gold can be seen easily as distinct dark flecks, enabling a pathologist to view the sample with greater magnification and in greater detail. 

Immuno-electron microscopy is used to diagnose a wide range of diseases and viral infections. It is also used for locating viral antigens in vaccines.