Antibody functions

Antibody

A protein produced by the immune system that identifies and neutralizes foreign objects like bacteria and viruses.

IgG

A monomeric antibody found in blood and extracellular fluid; it is the most abundant antibody in serum, responsible for crossing the placenta and activating the complement system.

IgA

An antibody that exists as a dimer in secretions and a monomer in blood; it is found at mucosal surfaces such as the gut, saliva, tears, and breast milk, playing a key role in neutralization.

IgM

A pentameric antibody that is the first type of antibody made during an infection, present in blood and lymph; it is crucial for strong complement activation and early defense.

IgE

A monomeric antibody that binds to mast cells and basophils and is involved in triggering allergic reactions and fighting parasites.

IgD

A monomeric antibody found on naive B cells; its role is unclear but it helps with B cell activation.