Figure 1

GM-CSF improves microglial yields from primary cultures. Mixed glial cells were prepared in culture medium supplemented with (+) or without (-) GM-CSF (0.5 ng/ml). Upon confluence (7–10 days), flasks were shaken overnight and the following day, supernatants were collected and microglial cell counts performed. Flasks were shaken once a week and following the second shake the relative percentage of microglia recovered from flasks cultured without GM-CSF was significantly reduced (**, p < 0.001). For reporting differences in microglial recovery, we normalized (i.e. divided) the numbers of microglia recovered from GM-CSF (-) flasks by those collected from GM-CSF (+) cultures to express the former as a percentage of GM-CSF (+)-containing conditions (set to 100%). Results represent the mean ± SD of two independent experiments.