Can you help me calculate the bioactivity of my cytokine?

Specific activity (expressed in units/mg) is a function of cytokine or growth factor purity and appropriate protein folding. To determine the specific activity, typically the readout of cytokine treatment is measured in a standardized bioassay. The ED50 (expressed in ng/ml), which is the concentration of cytokine or growth factor required to induce half the maximal biological response, is determined in the assay. The following formula can be used to convert the activity as an ED50 in ng/ml to specific activity in units/mg:
Specific activity (units/mg) = 10E6 / ED50 (ng/ml).
For example, the ED50 for our Human Leukemia Inhibitory Factor (hLIF) #8911 is approximately 0.85ng/ml (based on the median ED50 range from the webpage/datasheet) and therefore the specific activity would be 1.17 X 10^6 Units/mg:
10ug = 11,700 Units
50ug = 58,500 Units

最終更新日： October 6, 2025