AbstractInterleukin 6 (IL‐6) is a pluripotent cytokine with multiple effects on many different cell types. It is produced by a variety of cells in response to immunological and other stimuli. This unit describes a simple and sensitive assay for human, rat, rabbit, pig, and mouse IL‐6, based on IL‐6‐dependent proliferation of a murine B cell hybridoma cell line, B9. Support protocols discuss maintenance of B9 cells, preparation of IL‐6 standards, and production of IL‐6‐containing supernatant. In addition, IL‐6 ELISA kits for the measurement of human or mouse IL‐6 are available from a number of companies. These products are reliable, highly sensitive, and specific, and thus should be considered as an excellent (although more expensive) alternative, keeping in mind that bioactivity is not assessed with this approach
