Abstract
Subgingival plaque samples were cultured for the isolation of Peptostreptococcus micros from individuals with and without chronic periodontitis. Humoral antibody from each person reacted with P. micros in an indirect fluorescent-antibody test, but not all of the sera reacted in a passive hemolysis test. No correlations were observed between the presence of antibody reactive with P. micros and the isolation of P. micros or the gingival health of the individual.