Abstract: | In the past, it has been difficult to grow human diploid fibroblast cells at clonal densities. Newly devised cell culture media and rigorously controlled environmental conditions have greatly increased the ease with which such cells can be cloned. The present work was undertaken to determine whether, under appropriate conditions, diploid fibroblast cells from human embryonic lung, grow as well at clonal densities as in mass culture. The parameters studied were: (1) population doubling time, (2) in vitro proliferative capacity, (3) attachment, (4) percentage of non-dividing cells. In all cases essentially the same results were obtained for cultures at clonal densities and mass cultures. These results indicate that the behavior of these types of cells in clonal culture can be used to infer the behavior of individual cells and clones within a mass culture. |