[Antibody producing cells and immunoglobulin synthesizing cells lacking antibody function]

After primary immunization the first immunoglobulin-synthesizing cells which appeared, contained immunoglobulins devoided of antibody function. These cells were progressively replaced by antibody synthesizing cells. The results we reported here demonstrated that except the repartition of Ig between IgM and IgG, there are no differences in the molecular composition and in the rate of biosynthesis between these two populations of cells.