By Payal Khandelwal, PhD
Immunoglobulins (Ig), or antibodies (Ab), are the heavy globular plasma proteins produced in response to foreign bodies or antigens. They exist in five isoforms: IgA, IgD, IgE, IgG, and IgM. IgG provides the majority of antibody-based immunity. The ability of animal immune systems to produce antibodies against an injected antigen can easily be exploited to generate application-specific antibodies for both basic research and diagnostic applications. Additionally, the proliferation of recombinant DNA and protein technology has opened up previously uncharted territories in antibody construction. Substantial refinements in the upstream expression and production of antibodies have created a need for advanced downstream purification processes to remove contaminants such as albumin, transferrin, and α2-macroglobulin from native serum and host cell proteins (HCPs) from the recombinant source.