Lithium had no significant effect on percentage of GFP expressing live cells in RG3.6 cell cultures. (A) GFP-expressing cells are negative for propidium iodide (PI) staining. RG3.6 neurospheres were dissociated by trypsinization. The dissociated cells were stained with PI, a red fluorescent nuclear dye that specifically stain dead cells. The green GFP signal and the red PI staining were visualized and photographed using fluorescent microscope. (B) RG3.6 cells treated with NaCl or LiCl had similar GFP histograms. Flow cytometry analysis was performed on RG3.6 cell cultures treated with 3 mM NaCl or 3 mM LiCl for 3 days. Cells grown in non-FGF2 containing medium for 6 days were used as a negative control to gate GFP signal, since most cells grown in this condition were dead. (C) Quantification of the data shown in B. Lithium treatment had no significant effect on the percentage of GFP-expressing live cells in RG3.6 cell cultures.