IL-27 is expressed in activated antigen presenting cells including monocytes, endothelial cells, and dendritic cells, for example mouse CD4 splenocytes. This purified antibody has been tested for use in Flow Cytometry, ELISA and western blotting. Specific conditions for reactivity should be optimized by the end user. Expect a band approximately 26 KDa in size corresponding to the mature mouse p28 protein, a non-glycosylated polypeptide chain consisting of amino acids, by western blotting in appropriate cell lysate or extract.