Long-Term Cultivation of Human Cells (Chang) in Chemically Defined Medium and Effect of Added Peptone Fractions

Freshly explanted tissue cells and most established cell lines cannot be cultivated in vitro indefinitely in chemically defined medium unsupple-mented with serum (1). Yeast extract and peptone the stimulatory components of either serum or peptone requires that the test system include no other unknown material. Thus, there is need for a chemically defined medium that will support con-TABLE I Fructose 1-6 phosphate 100.0 Fischer et al. 3.200 / Glucuronolactone 1.000 J 1-Homocystine 1.0 1 Ergothionine HCI 1.0 I Glucose 1-phosphate 1.0 [ Citric acid 1.0 ! Beta-estradiol 0.100/Other components Thioctic acid 1.500 [ Cholic acid 20.0 [ Carboxymethyl cellulose 70L 250.0 J Whenever practical, purity of ingredients has been checked by paper chromatography and by electrophoresis. preparations are sources of growth stimulatory material which can alternate for serum in a limited number of cases (1, 2). To identify unequivocally * tinuous growth of ceils, but whose growth potential can be increased by adding the serum or pep-tone components. Medium A, shown in Table I, has been found to support continuous growth (11 months to date) of