The most cited neuronal cell culture supplement, B-27 Supplement is an optimized serum-free supplement used to support the low- or high-density growth and short- or long-term viability of embryonic, post-natal, and adult hippocampal and other CNS neurons. B-27 Supplement is provided as a 50X liquid and is intended for use with Neurobasal Medium or Neurobasal-A Medium for neuronal cell culture without the need for an astrocyte feeder layer.