Figure 1: Culture purity: at 5-6 DIV, cells were fixed and immunofluorescence staining was performed using the astrocyte marker GFAP (green), the neuronal marker NeuN (red), and DAPI stain (blue) for nuclei. Quantification of neuronal cells was done using 10 random fields from each of 3 experiments (×20 magnification). % of the total cells (DAPI stain) were recognized as neurons (NeuN positive, GFAP negative).