Non-precipitating protein antigens

When some protein antigens are heated with serologically unspecific proteins they cease to be precipitated by their antisera, and their behaviour in vitro approximates to that of non–precipitating haptens. Evidence from different sources suggests that this change in behaviour is brought about by the antigens combining with the other protein during the early stages of heat denaturation to form complexes, which after combination with antibodies still remain soluble.