In direct ELISAs, approximately 25% cross-reactivity with recombinant human (rh) IL-1 R6 is observed and less than 5% cross-reactivity with rhIL-18 R beta, rhIL-1 RI, and rhIL-1 RII is observed. Reconstitute at 0.2 mg/mL in sterile PBS. Endoxin level is