Immunolabeling

Immunolabeling is a means of localizing particular antigens within tissue. Immunolabeling is a methodological process where: 1) antibodies are used to identify antigens within an organism and 2) a tag (e.g. through fluorescence, gold beads, epitope tag, etc.) is added to a secondary antibody which binds to the primary antibody. When the secondary antibody is tagged with a piece of gold or any material of similar density, the metal is sufficiently impenetrable such that microscopy can be combined with immunolabeling. When the tagged antibodies are run through electron and/or light microscopy, the resulting image is of great precision, thus increasing the means of localization.

The applications of immunolabeling are numerous. For example, immunolabeling can be used to identify the effects of a drug on a particular organ. The effects are observed once the drug is administered, where the primary antibodies are added followed by the tagged secondary antibodies. The sample is then run through a light and/or electron microscope of some sort, and the resulting image helps identify which antigens are activated after a drug is induced. This technique also allows means of comparison where scientists can observe how these activated antigens may differ from the antigens prior to the administration of the drug. Thus, the applications of immunolabeling can be used for various fields such as pharmacology, molecular biology, biochemistry, and any other field where the precise location of an antibody is desired.

Immunolabeling Images
Diagram of Labeling

Immunolabeled Tissue