Detection and determn. of cytostatic activity - based on inhibition of cell growth under impregnated disc

摘要

The activity of cytostatic substances (esp. interferon) is detected and evaluated by (a) introducing indicator cells into an agarose medium, (b) placing at least one filter-paper disc on top of the agarose layer, (c) impregnating the disc with a soln. of the test substance (I), and (d) observing the diffusion of (I) in the disc during cell growth in the agarose. The size of the annular zone free of cell growth corresponds to the concn. of (I) required to inhibit cell multiplication. The method is highly sensitive; e.g., detectable inhibition zones are produced by 1-2 IU of human leucocyte interferon. It can be used, e.g., to determine the activity of interferon produced by genetically engineered bacteria, and can also be modified to determine the activity of inhibitors of cytostatic substances.