Immunoglobulin G （IgG） is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Lambda light chains are one of the two classes of light chains present on mammalian immunoglobulins. They are found in combination with kappa light chains. These chains are usually present in a 70:30 ratio of kappa to lambda. Anti-lambda light chain antibodies can nonspecifically bind to multiple isotypes of immunoglobulins.