Parameters for optimizing detection of transforming growth factors

Transforming growth factors (TGF) induce the soft agar growth of nontransformed cells, such as NRK-49F cells. This report describes culture conditions that optimize the detection of TGF by NRK-49F cells. Two aspects are dealt with in depth: the need to select an appropriate clone of NRK-49F cells and the need to select a culture medium that supports little or no background growth in the absence of added TGF. Evidence is presented to demonstrate that medium supplemented with heat-treated, dialyzed bovine plasma provides better conditions for assaying TGF than serum-supplemented medium provides.