Analysis of the optimal conditions for the adsorption of type III pneumococcal polysaccharide to plastic for use in solid-phase ELISA.
An economical, sensitive enzyme-linked immunosorbent assay (ELISA) method for measuring all isotypes of immunoglobulin specific for type III pneumococcal polysaccharide (SSS-III) is described, using 96-well polystyrene microtiter plates coated directly with antigen. To achieve substantial binding of SSS-III to plastic plates, the polysaccharide had to be dissolved in a buffer (0.1 M Hepes) of pH 4.0 or less. Optimal conditions for adsorption of SSS-III to plates were found to be pH 3.5 and a concentration of 1.0 microgram SSS-III/ml (0.1 microgram/well). Under these conditions, murine anti-SSS-III polyclonal or monoclonal antibodies could be detected to a limit of about 5-10 ng/ml. The implications of these findings for assays that use mixtures of polysaccharides adsorbed to plastic plates are discussed.
Elkins
K L
KL
Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852.
Stashak
P W
PW
Baker
P J
PJ
D000327:Adsorption; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D000942:Antigens, Bacterial / Q000008:administration & dosage*; D004306:Dose-Response Relationship, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007132:Immunoglobulin Isotypes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011135:Polysaccharides, Bacterial / Q000276:immunology; D011137:Polystyrenes; D013296:Streptococcus pneumoniae / Q000276:immunology*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007132:Immunoglobulin Isotypes; D011135:Polysaccharides, Bacterial; D011137:Polystyrenes; C026604:pneumococcal polysaccharide, type III