Interleukin-6 (IL-6) is suitable as a control for polyclonal or monoclonal anti-Interleukin-6 (IL-6) in immunological assays. It is recommended to reconstitute the lyophilized recombinant M-IL-6 in 10 mM HCl to 0.1-1.0 mg/mL to regain full activity; this can then be further diluted to other aqueous solutions.