IgG is the most common type of antibody found in blood circulation accounting for nearly 75% of serum antibodies. IgG is the main type of antibody found in blood and extracellular fluid, allowing it to control infection in the  body tissues. It binds to pathogens such as viruses, bacteria, and fungi, therefore providing protection against these infections. Anti-Human IgG whole serum plays a critical role in the estimation of elevated levels of IgG during various diseased states. It is also used as blocking reagents or negative controls in various in vitro diagnostic (IVD) test kits, and ELISA kits. It may be used in the detection of IgG levels in rheumatoid arthritis patients. It is used in the development and manufacturing of various qualitative and quantitative assays based on RID, IEP, ELISA, latex enhanced immunoturbidimetric assays, ouchterlony double diffusion, western blot, and precipitin assay intending to estimate IgG in various disease conditions in humans.