IL-1 refers to two proteins, IL-1α and IL-1β which are the products of distinct genes, but which are recognized by the same cell surface receptors. IL-1α is a potent immuno-modulator which mediates a wide range of immune and inflammatory responses. The purified BL1a-72 antibody is useful as the capture antibody in a sandwich ELISA when used in conjunction with the biotinylated BL1a-89 antibody as the detection antibody and recombinant mouse IL-1α ?(Cat. No. 562801) as the standard.