Archive for the ‘Antibody’ Category
The COX IV Antibody as a Loading Control Reagent
Loading controls are an important requirement in Western blotting and other gel electrophoresis techniques. The COX IV antibody is one of a number of reagents in our antibody catalog which is routinely used as loading controls.
Loading controls have several functions in gel electrophoresis. Antibodies against widely-expressed “house keeping” proteins, such as COX IV, are used to ensure samples have been evenly loaded across the gel. Loading controls also serve as internal positive controls, to be sure all reagents are working correctly and that the protein transfer is adequate for blotting. Finally, they may be used to standardize results across different blots.
The loading controls in our antibody catalog are always abundantly expressed proteins, and are often used as cellular markers. The COX IV antibody is a case in point, being used both as a mitochondrial marker and a mitochondrial loading control, in ELISA and Western blot assays. These antibodies are also used to study the role of COX IV in areas like lipid metabolism, hypoxia and cancer.
Cytochrome c oxidase (Complex IV, or COX), is the terminal enzyme complex of the respiratory chain, located on the inner mitochondrial membrane. A large hetero-oligomeric complex, it is composed of 3 large mitochondrial and 10 smaller nuclear encoded subunits, one of which is recognized by the COX IV antibody.
COX IV is constantly expressed at a high level, making it ideal as a loading control. However, expression is variable, in addition to which, many proteins run at the same size as COX IV(16kD). For these reasons, the COX IV antibody is often used with a tagged antigen, for example mouse monoclonal COX IV antibody may target recombinant COX IV with a GST tag.