What Are Actin Antibodies?

Actin antibodies are used to detect the presence of the protein actin. It is used solely for the purposes of biological or medical research, or in diagnostic pathology laboratories. Actin is studied mostly by scientists who investigate muscle or other associated systems, such as cytokinesis or binding proteins. However, because it is the most abundant protein in eukaryotic cells---more complex cell types containing internal structures known as organelles---it is often used as a positive control for experiments focused on other types of proteins.

Actin

• The protein actin is very strictly, or "highly," conserved throughout different organisms, from algae and bacteria to dogs and humans. It exists as single protein units, or monomers, which must be joined together to form the larger, globular protein. Actin is needed to make filaments in cells for the cell's movement as well as for the movement of organelles inside the cell. It is therefore essential for basic cellular processes, such as motility and cellular division.

Areas of Research Using Actin Antibodies

• Actin antibodies are are among the most routinely and widely used cell biology tools. Their application to experiments using immunohistochemistry, western blotting, immunoprecipitation, ELISA and flow cytometry, has a long, well-documented history of success. Most companies that produce and sell antibodies for research purposes produce primary antibodies that can be linked to a colored or fluorescent molecule, or that must be recognized by a secondary antibody linked to one of these visible molecules.

Actin Antibody in Immunohistochemistry and Immunnocytochemistry

• Actin is an essential component of the cell's messenger ribonucleic production, so it is usually present in significant quantities in the nucleus. Its presence here can be used as a positive control for IHC or ICC experiments. Actin is detected using antibodies that recognize its component amino acids. The visual observation that the actin antibody has been detected proves that the protocol used was correctly performed or formulated. Staining with actin antibodies serves as a positive control for other antibody staining to detect other types of proteins, either for research or medical diagnoses.

Actin Antibody in Western Blotting

• Western blotting is a method of protein detection and quantification using scientific procedures such as gel electrophoresis, immunoblotting and antibody hybridization. The protein of interest and the actin protein are electrophoresced through a gel, which allows proteins of different sizes to separate along a size gradient. The individual proteins are then transferred onto a special membrane, where they become immobilized. Actin antibodies are applied to the membrane to detect the immobilized actin protein, again serving as a positive control for the detection of the protein of interest. Because a known mass of actin protein is usually used, it is possible to compare this number to that of the protein of interest and thus determine its quantity.

Actin Antibody in Immunoprecipitation

• Again, because actin antibodies are so routinely used and well-studied, their unique ability to bind strictly to actin and their known size property are exploited as positive controls in immunoprecipitation experiments. Interactions that occur inside a cell can be studied by lysing the cell---facilitating its disintegration---and collecting the resulting lysate, which is essentially a "soup" of different proteins. By binding antibodies against a protein of interest and actin, and then applying the mixture to a column, it is possible to purify the antibody-bound protein and antibody-bound actin from other unwanted proteins. The detection of actin proteins by the actin antibody serves as proof that the immunoprecipitation procedure was successful.