A conjugated antibody (also known as a tagged, loaded or labeled antibody) is one that has been attached to a substrate such as an enzyme, toxin or inorganic compound. Modern immunoassay techniques frequently use proteins conjugated with a fluorescent dye. Contemporary antibody sources sometimes supply a wide range of both polyclonal and monoclonal conjugated antibodies. For the benefit of those who are new to this area, we thought it would be a good idea to provide a synopsis of what these proteins actually are, how they work and how they are used. Conjugated antisera are used in many research applications, from Western blotting to in vivo cellular analysis. Researchers are looking for two things – a strong signal and specificity to particular antigens. We at Novus Biologicals pride ourselves on having an extensive catalog of highly specific products, including antibodies tagged with the very latest and most effective fluorophores. Today, hundreds of antiserum have been conjugated with protein markers and dyes for laboratory use. These are highly specific to both the antigens they target, and the assay protocol used. Modern conjugation procedures are relatively straightforward, although processes like gel filtration and spectrophotometry can pose problems on occasion. Some antibody labels, such as PE and APC, can be expensive in the quantities needed for conjugation. Although antibody suppliers like us at Novus Biologicals supply our products solely for non-clinical use, conjugated monoclonals are also extensively used in cancer treatment. By locking onto specific antigens in cancer cells, they can deliver drugs, radiotherapy and toxins to those areas without damaging surrounding tissues. Such antibodies are commonly categorized into chemolabelled, radiolabelled and immunotoxin groups.
