Comparison of rhTF and hTF for supporting hybridoma cell proliferation, cumulative cell density, and antibody production. Sp2/0 hybridoma cells were cultured in serum-free medium supplemented with hTF or rhTF at 0.03, 0.1, 0.3, 1, 5, or 30 mg/L. The hTF and rhTF were compared at different degrees of iron saturation: Apo, iron-free; Partial, partially iron saturated; Holo, iron saturated. A. Comparison of hTF to rhTF for cell proliferation during log phase growth (day0 through day3). B. Comparison of hTF to rhTF for cumulative cell density. Cumulative cell density is the estimated area under the growth curve and is indicative of the total cell mass generated by a culture system. Units are given in cell-days/ml. C. Comparison of hTF to rhTF for antibody production. Error bars denote the standard deviation of triplicate cultures.