This antibody will recognize 10% of the non-denatured (native) precursor 31,000 MW mouse IL-1beta containing samples but will primarily detect all of the 17,000 MW mature molecule. However, in western blot analysis, the usual procedure of heating the sample in SDS with or without reducing agents will facilitate denaturing of the 31,000 MW IL- 1beta precursor molecule. Denatured IL-1beta will have a 18 kDa band.