METHOD FOR PREPARING CONTACT-INHIBITORY FACTOR

摘要

A method for preparing a biologically active factor that is capable of restoring contact-inhibition of growth in malignant cell type. The method comprises loading a mixture comprising culture medium conditioned by growth of a contact-inhibited cell culture and an ionic buffer to a chromatography column equilibrated with the same buffer and comprising a non-ionic hydrophobic affinity material as the adsorbant. The column is washed once with the same buffer until a peak of material elutes, a second time with the same buffer with decreased ionic strength which lacks sodium chloride until a second peak elutes, and eluting the factor with unbuffered purified water. The eluate is desalted by membrane filtration and dried. The method is conducted in the absence of a volatile precipitating agent.