Methods are taught for culturing mammalian cells, preferably human cells, to improve production of proteins, recombinant or endogenous. Methods are also provided for the growth and long-term survival of cell lines, particularly cell lines established from primary culture. Cell culture media are also provided, contained varying levels of selected amino acids, supplemented with various growth factors and trace elements. In additionally, the media are optionally serum-free, and preferably use an energy source other than glucose. The media are particularly suitable for the primary culture and long-term culture of human fetal cells.