Purity: > 95% by SDS - PAGE Format: Liquid. In Phosphate buffer saline (pH 7.4) . One of the most potent pro-inflammatory mediators is the early-acting cytokine interleukin-1 (IL-1), whose actions are regulated by the structurally related IL-1 receptor antagonist (IL-1 RA). IL-1 RA is a competitive IL-1 inhibitor and a powerful anti-inflammatory agent. Also, Several autoimmune and inflammatory diseases have been associated with an allelic polymorphism of the IL-1 RA gene. Recombinant human IL-1 RA was expressed in E. coli and purified by using conventional chromatography techniques.