Establishment of mouse neuroblastoma clone E 7 in serum-free medium.

Ninety-six clonal populations were derived from a wild mouse neuroblastoma cell population C 1300 in a serum-free medium containing commercially available serum growth-promoting proteins (GPP). From among these 96 lines the clonal population E 7 was chosen for further work because it displayed maximum spontaneous morphological differentiation. The neuroblastoma clonal population differs morphologically from the original population; it was defined both cytogenetically and by means of growth parameters. The cells of the neuroblastoma clone E 7 are hypertetraploid with two chromosome number modals - 88 and approximately 180-200. The majority of telocentric chromosomes in metaphases with a modal number of 88 chromosomes are identical with the chromosomes of mouse diploid cells. The cell generation time is 22 hours. The cells of the clonal population E 7 are highly sensitive to the action of ethanolamine, which induces morphological differentiation, so that the processes of 30% of the cells in the population are over 40 micron long. Electrophysiological studies showed that the cells of the neuroblastoma clonal population E 7 retain the character of excitable cells and they are thus suitable for studying some of the properties of nervous tissue cells.