Effect of heating on the binding to solid phase histone of IgG. Net A450 yielded by ELISA on histone coated wells reacted with purified human IgG and 10 blood bank donor (BBD) serum samples, incubated at 20°C or at 61°C (aggregation). Conjugate is goat antihuman IgG (Fcγ)-horse radish peroxidase