Abstract
By means of cell-suspension culture as described in Part 1, morphological changes in Yoshida sarcoma cells were studied by phase-contrast microscopy during the cultivation.
Those Yoshida sarcoma cells in ascites as well as those immediately after the start of tissue culture were well delineated. Their cell margin swayed slightly and slowly like monocytes, but the cells themselves did not move at all. Most of the nuclei were kidney-shaped and some were lobulated. Nucleoles were ovoid in shape and usually these were one or two distinct ones. Their nuclear membranes were likewise clearly visible.
At the recess of the nucleus there could be recognized a Golgi field on both sides of which there were mitochondria that exhibited slight motility. Cell mitosis could be observed in about 2 to 4 per cent of them.
After one day of culture, there was an increase in the number of cells and mitotic figures but no marked morphological chaeges were obseved.
After 4 days, the nuclei became lobulated or irregular in shape, nucleoles grew indistinct, mitochondria turned granular, and vacuolization of Golgi field occurred.
After eight days, the cells that had been swollen by the 7th day were completely destroyed, and among these disintegrated cells there were a few, scattered, new cell with high celluar activity.
After 12 days, even these newly-fosmed cells were mostly destroyed and only a few survived.
When these few surviving cells together with the culture medium were injected into the abdominal cavity of rats, 11 days later the animals developed ascites containing many Yoshida sarcoma cells.
Apart from these experiments, various other cytological studies were carried out during the various stages of tissue culture and particularly fluorescence microscopy provided unique findings on the cultured cells.
