Large Amounts of Non-agglutinating Anti-erythrocyte IgG in Primary Antisera

Abstract

IT is generally accepted that IgM are synthesized before IgG antibodies. This sequence could depend on the characteristics of the antigen, its route of administration, the dosage used, and the animal species studied¹. There is some doubt as to whether IgM antibodies are predominant in some early primary antibody responses^2–4. This question arises in part from the fact that haemagglutination is more sensitive for detecting IgM than IgG antibodies^2,5,6; and in part from the observation that haemolytically inefficient IgG antibodies are undetected in the Jerne plaque technique⁷ unless indirect procedures are used^8,9. Indeed, sera obtained soon after injection of proteins may have more IgG than IgM precipitins^10–12. Thus there is a need for re-evaluation of the magnitude of the IgG response in the early stages of antibody production. Evidence is presented that sera from chickens immunized with sheep red blood cells (SRBC) contain more IgG than IgM antibody 6 days after injection.