Is DNA synthesis a requisite for the differentiation of B lymphocytes into immunoglobulin-secreting plasma cells?

A great amount of conflicting evidence has been reported concerning the relationship between DNA synthesis and the differentiation of immunoglobulin-secreting cells. With the development of flow cytometry, it has become possible to analyze lymphocyte populations by making rapid and accurate measurements of cellular DNA content, and by estimating the fraction of cells that synthesize DNA. Application of these techniques to an in vitro culture system stimulated by the T-dependent sheep red blood cell antigen has allowed us to investigate cell division in populations of antibody-forming cells. DNA synthesis is apparently not a requisite for the differentiation of immunoglobulin-secreting cells.