[A highly sensitive, homogeneous method for determining antibodies and antigens by using liposomes, monoclonal antibodies and complement].

A simple and sensitive method for the determination of Francisella tularensis antigen and antibodies to this antigen by means of the complement lysis of liposomes sensitized with F. tularensis lipopolysaccharide (LPS) is proposed. The possibility of participation of monoclonal antibodies (McAb) in the complement-dependent lysis of liposomes has been studied. The method permits the detection of 50-100 ng/ml of soluble LPS antigen in the presence of antiserum or McAb IgG F-B11-x and of 50-10 ng/ml of it in the presence of IgG F-B11-x and anti-IgG within 90 minutes.