Long-term Cultivation of Pseudo-diploid Cells of Human Tumor Origin

One cell culture line was obtained from ascites fluid of a case diagnosed as reticulosarcomatosis. After about 50 days lag period, we were able to obtain a cell line which could grow continuously in vitro. This cell line has grown only in a floating state. At the present time, the doubling time of the culture is within 30 hours and the cells can multiply actively. Chromosomal analysis showed that the modal number of this line was 46, but the karyotype was not the same as that of the normal human cells. So far this pseudo-diploidal character has not changed in its successive culture.