An antibody (Ab), or immunoglobulin (Ig), is a large protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as those that exist on …

What do antibodies look like? Each antibody structure consists of two heavy chains and two light chains, which join to form a Y-shaped molecule. Each type of antibody has a different amino acid sequence …

Feb 19, 2026 · Antibody, a protective protein produced by the immune system in response to the presence of a foreign substance, called an antigen. Antibodies recognize and latch onto antigens in …

Sep 17, 2022 · Different antibody classes allow the immune system to respond effectively in different locations and stages of infection. Each antibody type has structural features that determine where it …

Discover the roles of antibodies and antigens in your body's defense. We explain the difference between an antibody and antigen and how they antibodies detect and flag harmful antigens to protect your …

Aug 3, 2023 · Each antibody has two light chains that are identical and only one of the two (lambda (λ) and kappa (κ)) light chains is present per antibody in mammals; therefore either of the chains can …

Learn what an antibody is, how it works in the immune system, the main antibody types, and their uses in vaccines, diagnostics, and medical therapies.

Sep 25, 2025 · IgG: The most abundant antibody found in the body. It can help to block infections caused by bacteria, viruses, parasites, or other disease-causing organisms.

Mar 18, 2026 · An antibody is a protein component of the immune system that circulates in the blood, recognizes foreign substances like bacteria and viruses, and neutralizes them.

Explore the function of antibodies in the immune system, how antibodies are used and produced in research, and how to choose the best antibody for you.