Immunoglobulins that bind to uncoated ELISA plate surfaces: appearance in mice during infection with lactate-dehydrogenase-elevating virus and in human anti-nuclear antibody-positive sera.
Immunoglobulins present in the blood plasma of mice infected with lactate-dehydrogenase-elevating virus (LDV) were found to bind strongly in the presence of 0.05% Tween 20 to the uncoated surfaces of wells of certain ELISA plates with previously recognized high protein-binding capacity. The binding was readily distinguishable from non-specific background binding of immunoglobulins present in normal mouse plasma. The binding components absorbed to protein A and had molecular weights in the 150-300 kDa range. Binding of the purified IgG fraction was progressively inhibited by increasing the concentration of Tween 20 in the diluent and by preincubation of the fraction at pH 3-4 for 10 min. The appearance of plate-binding IgM and IgG during LDV infection corresponded approximately with previously reported time courses of appearance of IgM- and IgG-containing circulating immune complexes and of specific IgM and IgG anti-LDV antibodies in LDV-infected mice. We conclude that complexes of IgG and IgM with LDV antigens have a much higher affinity for ELISA plates with high protein-binding capacity than uncomplexed immunoglobulins. Immune complexes did not significantly bind to ELISA plates with low protein-binding capacity, which, therefore, are suitable for measuring specific antiviral antibodies. Preliminary experiments with human anti-nuclear antibody-positive serum samples demonstrated markedly elevated non-specific binding of immunoglobulins to high-binding-capacity ELISA plates.
D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis* / Q000276:immunology; D000936:Antigen-Antibody Complex / Q000032:analysis*; D000956:Antigens, Viral / Q000032:analysis / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007772:Lactate dehydrogenase-elevating virus / Q000276:immunology*; D051379:Mice; D010969:Plastics; D013997:Time Factors; D014777:Virus Diseases / Q000276:immunology
D000914:Antibodies, Viral; D000936:Antigen-Antibody Complex; D000956:Antigens, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D010969:Plastics