Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Ig
Medically reviewed by Min Clinic Staff | Updated: January 2026
Ig: Abbreviation for immunoglobulin, a protein produced by plasma cells and lymphocytes. Immunoglobulins are an essential part of the body's immune system which attach to foreign substances, such as bacteria, and assist in destroying them.
The classes of immunoglobulins are immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin D (IgD) and immunoglobulin E (IgE).