According to different biotins conjugated with antibodies, IHC staining methods can be classified as immunofluorescence, immunoenzymological staining and affinity histochemistry. According to different kinds of procedures, immunohistochemistry staining can be divided into subtypes of direct staining (one-step staining) and indirect staining (two-step, three-step or multi-step staining).
|In immunoenzymological staining enzyme-labeled antibodies are used to bind specific antigens in tissues samples or cultured cells. Aft er adding in substrate of enzyme it generates insoluble or high-electronic density particles that could be localized under light microscope or electronic microscope. Compared to immunofluorescence staining, immnuenzymological staining has more accurate localizing, better contrast ratio, and samples are able to be stored for a long time.|
|Immunocolloidal gold technique is a kind of technique that uses colloidal gold as a marker. This kind of special metal particle is hydrosol form of gold and it can bind proteins rapidly and stably. Moreover, colloidal gold has little effect on biological activity of natural proteins. Therefore colloidal gold is an ideal material which can be conjugated with primary, secondary antibody or some other kinds of proteins that can bind IgG (e.g. Staphylococcus A protein) to localize certain antigens in sectioned tissue or cultured cells. Due to differences in size of particles of colloidal and its high electronic density, immunocolloidal gold technique is suitable for single or multi-label detection under immune-electron microscope, and light microscope,too.|