The lung-colony assay: extension to the Lewis lung tumour and the B16 melanoma--radiosensitivity of B16 melanoma cells.

Experiments are described which demonstrate that a lung-colony assay can be used to study the viability of unknown cell populations from the B16 Melanoma or the Lewis Lung Tumour. It is shown that the number of lung colonies formed can be increased by the addition of plastic microspheres to the injected cell suspension or by pre-irradiating the lungs of the recipient mice. The colony technique has been used to isolate melanotic and amelanotic cell-lines from the B16 Melanoma which were found to have different growth-rates. In vitro radiation survival curves for B16 Melanoma cells have also been established, and these have parameters in the usual range for mammalian cells.