Process for producing biologically active factors

A process for the concentration of biologically active factors having an inhibiting effect on the growth of neoplastic cells from cell homogenates of fetal or juvenile tissues or body fluids which contain said biologically active factors, which comprises the steps of:

• (a) non-destructively sterilizing said cell homogenates with an acid or diethylamine;
• (b) separating the components of cell nucleus and cytoplasmic components from the sterilized starting material;
• (c) enzymatically decomposing lipids and carbohydrates which are obtained from step (b) with an enzyme selected from the group consisting of lipase, proteinase and peptidase;
• (d) separating the cell substrate and recovering a factor having a molecular weight from about 600 to about 1,000,000;
• (e) forming a conjugate with DNA isolated from a cell homogenate with an inert carrier and forming a biologically active affinity sorbent means responsive to selective separation with said conjugate;
• (f) selectively separating said biologically active factors by elution on said affinity sorbent, and then
• (g) separating said biologically active factors from said affinity sorbent by electrophoresis or by a buffer solution,
• whereby an enriched amount of said biologically active factors is recovered.