The primary antibody response of individual spleen cells in diffusion chambers.

Spleen cells from non-immunized mice were mixed with sheep red blood cells and incubated in diffusion chambers implanted in the mouse peritoneal cavity. At 6 and 7 days an increase was noted in the proportion of plaque-forming cells in the chambers and this was accompanied by the appearance of haemagglutinin and haemolysin in the chamber fluid. Excess antigen was not observed to depress this proportion of plaque-forming cells.