In this experiment, diversity of the cells in response to complement mediated cytolysis employing syngeneic rat anti-sera was studied. More than 50% of the glass grown cells were lysed while only 19% of the plastic grown cells were lysed by the specific immune sera of syngeneic rats. This finding suggests that growth in plastic culture wares selects cells with resistance to complement mediated cytolysis.

It seems likely that the previously reported enhanced tumorigenicity of plastic grown T-333 cells is due to clonal selection of cell subpopulations which can better tolerate at least one arm of the in vivo immune surveillance system.