Growth of mouse neuroblastoma cell line in a defined medium

The mouse neuroblastoma tumor line Cl300, clone Neuro-2a, can proliferate in a serum-free synthetic medium supplemented with insulin, transferring, progesterone, selenium and putrescine (N2 medium), with a marked increase in cell number as compared to the optimal 10% serum containing medium. More extensive and elaborate neurite formation with contacts is seen in N2 that in serum supplemented medium. However, electron microscopic studies of the cells grown in N2 lack the formation of synapses, in contrast to the cells grown in serum supplemented medium where at least primitive stages of synaptogenesis are common.