In sandwich ELISAs, less than 0.5% cross-reactivity with recombinant mouse (rm) IL-2, rmIL-4, rmIL-15, and recombinant human IL-21 is observed. Reconstitute at 0.2 mg/mL in sterile PBS. Endoxin level is <0.30 EU per 1 μg of the antibody by the LAL method