IgG

American

Immunology.

immunoglobulin G: a class of circulating antibodies predominant in serum, produced by plasma cells and memory cells in response to pathogens and other foreign substances, able to pass through the placental wall to the fetal circulation to impart immune defense for the period of infancy.

Etymology

Origin of IgG

First recorded in 1960–65

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

"But IgG antibodies never cross the cell layers and they can never make it inside the cysts."

From Science Daily • Nov. 19, 2025

None of these differences, like IgG which is also in human breast milk, is necessarily harmful to humans.

From Salon • Jan. 19, 2024

The current COVID-19 vaccines mainly stimulate an IgG antibody response in the body, and earlier studies have shown that their ability to protect against infection with the new Omicron variants of the virus is limited.

From Science Daily • Jan. 10, 2024

There are five different classes of antibody found in humans: IgM, IgD, IgG, IgA, and IgE.

From Textbooks • Jun. 19, 2013

IgG is a major antibody of late primary responses and the main antibody of secondary responses in the blood.

From Textbooks • Jun. 19, 2013

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023