Long-term growth of chicken fibroblasts on a collagen substrate

In 3 separate experiments, cells derived from chick embryo muscle explants have been grown in either Waymouth's medium or Ling's (AN.54) medium with 20% human placental cord serum. Continuous transfer and new outgrowth from a succession of 2 × 2 mm fragments has continued for periods of 24 to 44 months. Continuous growth was achieved only on a collagen substrate, and no continuous growth was obtained when cells were transferred to glass. When incubator temperature was raised to 43 °C over a period of 1 month, new cell types developed and had the capacity to both survive and grow directly on glass for several months.