As an improvement on the commonly used additives for neuronal cell culture, the B-27 additive (excluding vitamin A) is a customized version of the initial B-27 additive after removing vitamin A (retinol acetate). B-27 additive (excluding vitamin A) is a serum free additive that is an ideal choice for cultivating neural progenitor cells and neural stem cells, whether in suspension or in adherent monolayer culture, without inducing differentiation. B-27 additive (excluding vitamin A) is provided in 50X liquid form and is suitable for use with Neurobasal or Neurobasal-A media for neuronal cell culture without the need for an astrocyte trophoblast.