Addition of iron and zinc complexes to Eagle's Minimal Essential Medium is sufficient to induce and support the proliferation of B16 melanoma cells.

It was observed that the addition of zinc and iron tartrate complexes to the Eagle's Minimal Essential Medium was sufficient to support the proliferation of murine B16 melanoma cells in this simple extracellular protein-free medium. The addition of these trace elements to the serum-depleted EMEM induced growth of B16 cells as did the addition of serum. This implicates that this test, often used in the search for mitogenic factors, does not discriminate between the real mitogens and the nutrients necessary for cell growth.