Happonen R-P, Arstila P, Viander M, Soderling E, Viljanen M: Comparison of polyclonal and monoclonal antibodies to Actinomyces and Arachnia species, Scand J Dent Res 1987; 95: 136-43 Abstract -Polyclonal (PoAbs) and monoclonal (MoAbs) antibodies were produced to Actinomyces israelii serotypes 1 and 2, to Actinomyces naeslundii, and to Arachnia propionica, and their specificities were studied by an enzyme immunoassay (EIA), Ali PoAbs except those to A, propionica reacted also with at least one other Actinomyces species. Only the MoAb to A, naeslundii proved to be more specific than the corresponding PoAbs, This MoAb did not crossreact with other Actinomyces or Arachnia species, nor with any other anaerobic or aerobic bacteria s.tudied by inhibition EIA, Immunoblotting studies indicated that the antibody specific to A, naeslundii is directed against a large molecular weight antigen (>150 kd), probably polysaccharide in nature. The produced PoAbs and MoAbs can be u.sed for furtber analyses of the andgenic determinants of different Acdnomyces and Arachnia species.