Specificity of monoclonal antibodies against Escherichia coli K-12 lipopolysaccharide

Three monoclonal antibodies against the lipopolysaccharide (LPS) of Escherichia coli strain K-12 were obtained after immunization of BALB/c mice with heat-killed bacteria and were serologically characterized by hemagglutination, enzyme-immunoassay, Western, dot, and colony blot using as antigens bacteria, LPS, de-O-acylated LPS, dephosphorylated LPS, the core oligosaccharide and synthetic partial structures representing a di-, tri-and tetrasaccharide of the K-12 outer core region. In addition, deacylated LPS and synthetic oligosaccharides were covalently linked to bovine serum albumin resulting in artificial glycoconjugate antigens. In all assays used, the antibodies were specific for K-12 LPS. These antibodies detect E. coli K-12 LPS in its isolated form as well as on the surface of bacteria and are, thus, useful for all working with this microorganism.