Immunochemical Properties of Native and Heat Denatured Ovalbumin

Affinity antibodies purified against native ovalbumin were found more reactive (higher avidity) against heat‐denatured ovalbumin than against the native molecule by three different immunochemical methods. Quantitative immunoprecipitation in soluble phase revealed that more antigen‐antibody complexes were insoluble with native ovalbumin than with heat‐denatured ovalbumin; 25% of antibodies were still present in supernatant at equivalence as measured by ELISA. At the same conditions with heat‐denatured ovalbumin, very small amounts of antibodies were precipitated while almost no activity was found in the supernatant. Classical ELISA or competitive ELISA test allowed detection down to 100 ng/mL of native ovalbumin and 10 ng/mL of denatured ovalbumin.