Phenotypes of tumor cell lines grown as single cell type tumor spheroids and fibroblast/tumor composite spheroid using the hanging drop method.

Spheroids were grown from tumor cells alone (100%), or mixed with different proportions of wild type mouse embryonic fibroblasts. 50% and 10% refer to the amount of tumor cells in the composite spheroids. Spheroid morphology was assessed and photographed under a phase contrast microscope using a Nikon D3000 digital camera 4 and 6 days after seeding.