Properties of Immunoglobulin G (IgG): 

• Is produced as part of the secondary immune response to an antigen and protects the body against infection by remembering which pathogens it has been exposed to previously
• Is typically found as monomers 
• Has an average half-life of 23 days
• Is a small molecule capable of penetrating intracellular and extracellular spaces
• Protects the growing fetus against infections and is the only isotype that traverses the placenta
• Binds antigens with both low avidity and high affinity
• Involved in mediating opsonisation due to their affinity for Fc receptors on phagocytic cells
• Protects against pathogens found in blood and tissues
• Participates in neutralization of toxins, precipitation, and complement fixation
• Attracts microorganisms and stimulates phagocytosis