Which immunoglobin is present in highest amount in human blood serum?
The correct answer is IgG.
Of the five immunoglobulin isotypes, immunoglobulin G (IgG) is most abundant in human serum. The four subclasses, IgG1, IgG2, IgG3, and IgG4.
IgG accounts for about 10–20% of plasma protein.
Each IgG molecule consists of the basic four-chain immunoglobulin structure—two identical H chains and two identical L chains (either kappa or lambda)—and thus carries two identical antigen-binding sites.