The generation of antibody diversity. III. Variation in the specificity of antibody produced within single clones of antibody‐forming cells <i>in vitro</i>

Abstract

Abstract Within single clones of antibody‐forming cells cultured in vitro , variant cells making different antibody specificities are generated at a high rate. This has been demonstrated in 2 ways. First, at limiting dilutions, mixtures of plaqueforming cells (PFC) of different specificities occur significantly more often than is expected from chance overlap of 2 clones. Second, PFC releasing uncommon, highly cross‐reactive antibody grow into clones which are much smaller than average, in mitogen‐stimulated cultures. This suggests that PFC of such rare types arise within clones initially producing other antibody specificities.