STUDIES ON THE QUALITY OF NEUTRALIZING BACTERIOPHAGE ANTIBODIES PRODUCED BY SINGLE CELLS. II. EVIDENCE INDICATING THAT DIFFERENT CELLS OF A LYMPH NODE PRODUCE DIFFERENT KINDS OF ANTIBODY AGAINST THE POLYSACCHARIDE ANTIGEN O-9,12 OF SALMONELLA.

Single lymphoid cells from a population producing O antibody anti-9,12 were tested with bacteria sharing only O-9, only O-12 or the complete O-9,12 with the immunogen. Twenty-three per cent of the 420 cells tested attached the motile test bacteria onto themselves, which has been shown to be caused by an antigen—antibody reaction. Out of the positive cells approximately one-quarter were capable of reacting with antigen O-9 but not with O-12, another quarter were capable of reacting with O-12 but not with O-9, and almost a half reacted only with bacteria sharing the complete O-9,12 with the immunogen. The number of cells capable of reacting with O-9 and with O-12 could not be accurately determined but it appeared to be small.