Assay 1: The ED50 determined by the stimulation of IFN-gamma production with murine splenocytes co-stimulated with IL-18 is < 0.1 ng/ml, corresponding to a specific activity of > 1 x 107 units/mg. Assay 2: The activity is determined by its ability to stimulate the proliferation of 2D6 cells. The expected ED50 is < 0.1ng/ml, corresponding to a specific activity of > 1 x 107 units/mg.
SDS-PAGE Activity assay The optimal working dilution should be determined by the end user.
Lyophilized from 1 x PBS, pH 7.2.
Store at -20°C. Reconstitute in 1x PBS, pH 7.2-7.4 to a concentration of 0.1-1.0 mg/ml. Do not vortex. For extended storage, it is recommended to be further diluted in buffer containing carrier protein (e.g. 0.1% BSA) and stored in aliquots at -20°C to -80°C.