In vitro induction of a primary response to the dinitrophenyl determinant.

Primary antibody response against the dinitrophenyl group has been elicited in vitro after the stimulation of normal mouse spleen explants with 2,4-dinitrophenyl (DNP)-hemocyanin or alpha-DNP-poly-L-lysine (PLL). Antibodies were detected in the culture medium by the inactivation of DNP-T4 phage. The specificity of the reaction was manifested by the lack of the capacity of the medium to inactivate the unmodified bacteriophage and by the inhibition of the inactivation of DNP-T4 with DNP-lysine.