The use of normal filter paper for "dot-immunobinding assay" of some antibodies

Normal filter papers were used for specific detection of tiny amounts of antibodies against two penicillin amidase molecular forms from Escherichia coli, monoclonal antibodies of IgG and IgM class against lipopolysaccharide from Citrobacter O36 and IgM antibody against glycoprotein N from human red blood cells. For colour detection of antibodies bound to proper antigens adsorbed on the paper, second antibody-horse radish peroxidase conjugates and hydrogen peroxide with 4-chloronaphthol were applied. The use of filter paper for dot-immunobinding assay of antibodies gave similar results to those obtained with expensive nitrocellulose sheets used by other authors.