Abstract: Murine anti-Treponema pallidum monoclonal antibodies were employed in the detection of low numbers of pathogenic treponemes. Monoclonal antibodies were used as a primary antibody source in a solid-phase immunoblot assay system. All monoclonal antibodies assayed were capable of detecting ca. 1.0.times.10.sup.3 to 2.5.times.10.sup.3 treponemes. Of 13 monoclonal antibodies examined, 3 were able to detect 10.sup.3 virulent treponemes, and 1 of these antibodies was able to reveal the presence of as few as 500 organisms. Western blot analyses showed that all anti-T. pallidum monoclonal antibodies exhibiting high sensitivities for the detection of T. pallidum cells were directed against an abundant, 47,000-48,000 dalton surface-exposed antigen of the organism. With two possible exceptions, the monoclonal antibodies tested reacted specifically with T.

Abstract: Continuous hybrid cell lines for producing monoclonal antibodies directed against antigens of Treponema pallidum have been developed. The hybrid cell lines were established by fusing differentiated lymphoid cells primed with antigens of Treponema pallidum with hybridoma cells. The resulting fused cells were cloned, isolated, cultured and characterized as to antibody specificity against antigenic determinants of Treponema pallidum.

Abstract: Continuous hybrid cell lines for producing monoclonal antibodies directed against outer membrane antigens of Haemophilus influenzae type b have been developed. The hybrid cell lines were established by fusing differentiated lymphoid cells primed with outer membrane antigens of Haemophilus influenzae type b with hybridoma cells. The resulting fused cells were cloned and characterized as to antibody specificity against antigenic determinants of outer membranes of Haemophilus influenzae type b. One hybrid produces a monoclonal antibody which is capable of conferring passive immunity on Hib infected hosts.