1
: a class of immunoglobulins including the most common antibodies circulating in the blood that facilitate the phagocytic destruction of microorganisms foreign to the body, that bind to and activate complement, and that are the only immunoglobulins to cross over the placenta from mother to fetus
2
: an antibody of the class IgG

Examples of IgG in a Sentence

Recent Examples on the Web
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Other serology tests are designed to detect IgG antibodies, which take longer for the body to produce but function to provide longer term immunity. Matthew Binnicker, Forbes, 7 Sep. 2024 Mice given IgG from these patients, as well as healthy controls, then underwent a battery of tests. Byjennifer Couzin-Frankel, science.org, 21 June 2024 The most common components of colostrum supplements are immunoglobulins (especially IgG), growth factors, and lactoferrin. Isabel Vasquez Rd Ldn, Health, 2 July 2024 Some allergy tests look for another protein, immunoglobulin G (IgG). Rachel Murphy, Verywell Health, 26 May 2023 That IgG can move from the blood across the mucosa. Steven Strogatz, Quanta Magazine, 5 Apr. 2023

Word History

First Known Use

1965, in the meaning defined at sense 1

Time Traveler
The first known use of IgG was in 1965

Dictionary Entries Near IgG

Cite this Entry

“IgG.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/IgG. Accessed 26 Nov. 2024.

Medical Definition

1
: a class of immunoglobulins that include the most common antibodies circulating in the blood, that facilitate the phagocytic destruction of microorganisms foreign to the body, that bind to and activate complement, and that are the only immunoglobulins to cross over the placenta from mother to fetus
2
: an immunoglobulin of the class IgG

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