This antiserum against IL-6 has been tested for use in neutralizations, ELISA, immuno-histochemistry, radioimmunoassay, immunoprecipitation and immunoblotting. Reactivity in other immunoassays is unknown. For immunoblotting use the supernatants or lysates of 2 x 106 endotoxin-stimulated human peripheral blood mononuclear cells (PBMC). PBMC are stimulated for 24 hours with 1% (v/v) human serum plus 10 ng/mL E.coli LPS. For immunohistochemistry either paraffin fix or cryofix tissue. For immunoprecipitation, pre-clearing with a non-specific rabbit IgG is helpful to reduce background.