The microagglutination technique is used to determine the presence of antibodies in test specimens using a microtiter plate in which F. tularensis antigen coated latex particles are added to serial dilutions of patient sample. The microtiter plates are incubated with diluted human serum and appropriate controls. Any antibody to F. tularensis is bound to the F. tularensis antigen coated latex particles in the plate well. After the incubation period, each well is observed for the presence or absence of agglutination.