This question is part of the following Ask The Expert session:
Yes. Each cytokine is tested for performance using cell-based bioassays that include proliferation, induced cytokine secretion, cytotoxicity, and others. Before a cytokine is released to the public, a bioactivity specification is established based on the consistent performance of a minimum of three bulk lots. After that, each new bulk lot must meet this defined activity. Lyophilized vials are also tested for bioactivity following each new bottling run and must meet the specification. In addition, controlled stability testing is done to ensure that the cytokine retains its specified activity during storage. Details regarding activity testing for a given cytokine are regularly shared during audits of our facilities.