A method for autoradiographic studies of single clones of plaque forming cells

By limiting dilution of B lymphocytes from spleens of immunized mice, microcultures were obtained that contained only one clone of plaque forming cells (PFC). The cultured cells were labelled with [14C]thymidine for varying periods of time. Plaques were obtained in monolayers of sheep erythrocytes in plastic dishes. After fixation with glutaraldehyde, the bottoms of the dishes were stripped off and autoradiograms prepared. By this method, it is possible to determine the proportion of labelled PFC within a given clone and to quantitate the incorporation of label. The method described can be applied to study the incorporation of other labelled molecules and for cytochemical investigations.