Microbiology Immunology ea5e055d True of the following is/are- A IgA crosses placenta B Half life of IgG is 23 days C IgD is heat stable D IgE has highest carbohydrate content High-Yield Explanation Half life of IgG is approximately 23days Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pf:96