Which is a gamma globulin protein?

• A. CRP
• B. Immunoglobulins
• C. Albumin
• D. Transferrin

Answer: (B)

Gamma globulins are the antibody proteins that defend the body in humoral immunity. They are produced by plasma cells and comprise the immunoglobulin classes IgG, IgA, IgM, IgD, and IgE. In serum protein electrophoresis, these antibodies populate the gamma region, distinguishing them from other serum proteins. The other options serve different roles: CRP is an acute-phase protein rising during inflammation, albumin is the major plasma protein in the albumin fraction that maintains oncotic pressure, and transferrin is a beta-globulin that transports iron. Therefore, the gamma globulin proteins are the immunoglobulins.