Synthesis of Multiple Immunoglobulin Classes by Single Lymphocytes

There is good evidence that, in agreement with the principles of clonal selection, the immunoglobulin molecules synthesized by one B immunocyte, or by a clone of these cells, are uniform with regard to the Fv portion; that is, they have a uniform antibody-combining site and a uniform idiotype (reviewed by Mäkelä and Cross 1970). This condition applies both to the membrane-bound immunoglobulins (Raff et al. 1973) and to the secreted molecules (Mäkelä 1968).