Factors promoting the establishment of primary cultures of liver cells fromXenopus larvae.

The requirements for establishment and survival of primary cultures of larval amphibian liver cells were investigated.Plating efficiency was found to be enhanced by a collagen substrate, by diluted conditioned medium from an adultXenopus kidney cell line and by high initial cell densities. Plating efficiency was highest at a tonicity of 165-220 mOsm/kg. In cultures with undiluted conditioned medium the increase in cell number was 50-60% greater than in controls, where it was about 2-fold between day 3 and 6 of culture. Conditioned medium from theXenopus kidney cell line is assumed to contain at least two components, which are effective at different concentrations and stimulate either plating efficiency and cell aggregation or cell proliferation.In cultures without collagen sheets, cell flattening is greatly reduced, indicating that cell shape is also dependent upon the substrate.