Culture of Lymphocytes and Hemopoietic Cells in Serum-Free Medium

Freshly explanted lymphocytes and hemopoietic cells can grow and differentiate to terminally functioning cells in culture. Such cultures provide an opportunity to study, in cells not previously subjected to in vitro selection, such phenomena as induction of growth in physiologically resting cells, immune recognition, and the function of specific polypeptide factors and cell surface receptors. There are circumstances in which it would be desirable to perform these cultures in the absence of serum. One may wish to assay or study the function of added polypeptide factors that may already be present in serum in unknown concentrations. In other situations, the desired responses may be inhibited by substances in serum, or may be induced via mechanisms irrelevant to the one under study. Particularly significant in the case of immune responses are the antigens and antibodies contained in serum over which the experimenter has no control. In eliminating serum from the cultures to avoid interpretational difficulties, it is important not to introduce new ones. This could happen if responses in serum-free conditions were inferior to those obtainable with serum through failure to fulfill nutritive requirements of the cells. When the conditions described here were developed, emphasis was placed on achieving responses in serum-free cultures that were at least as good as those in conventional conditions. As it turned out, responses in serum-free cultures significantly surpassed those normally seen in conventional serum-containing media, particularly in lymphocyte cultures [Iscove and Melchers, 1978; Iscove et al., 1980; Schreier, 1981].