Table 2.

The proportion of MGC in low-density PR culture does not change significantly over the in vitro period

Days in vitro	Percentages of Müller glial cells
	Control	FGF-2	EGF
3	0	0.06	0.05
5	0.06	0.15	0.23
7	0.04	0.25	0.41

After 3, 5, and 7 d in vitro, cells immunolabeled with anti-vimentin antibody were counted on 25 fields on each coverslip from four separate experiments with a 40× fluorescence objective. The relative percentages of MGCs in PR cultures were determined by comparing the number of MGCs at each time with the number of living PRs after 24 hr in vitro. In absolute numbers, 0.15% MGCs represent 69 MGCs for 28,400 live FGF-2-treated PRs at 5 din vitro. These data show that the proportion of MGCs did not increase significantly over the period of cell culture, even in the presence of FGF-2 or EGF in the medium.