Immunoglobulin G (IgG) is an antibody that protects the body from infections, it can bind to viruses, bacteria and fungi. It is the most abundant antibody found in blood, lymph fluid, cerebrospinal fluid and peritoneal fluid and is essential in the humoral immune response. IgG uses agglutination to immobilize pathogens and allows phagocytic immune cells to recognize the pathogen by using opsonization. It can do this because it is a monomeric immunoglobulin made of two heavy chains and two light chains, making up two antigen binding sites. IgG is highly variable due to its composition of amino acids in the terminal portion. The C terminal is used for binding with the cell membrane, the complement system and allows it to pass through the placenta, thus providing protection to the fetus, which no other immunoglobulin can do. Thanks to the abundance and specificity towards antigens, IgG is the principal antibody used in immunological research and clinical diagnostics, making it a great option for ELISA. IgG is retained in the body for long periods of time, the longevity in serum makes it useful for immunization. Detection of IgG is used for indicating prior infection and vaccination.

The entire kit may be stored at -20°C for up to 1 year from the date of shipment. Avoid repeated freeze-thaw cycles. The kit may be stored at 4°C for up to 6 months. For extended storage, it is recommended to store at -80°C.