Quantitative expression of cell markers in isolated RGCs. A: Quantitative real-time PCR for glial fibrillary acidic protein (GFAP), syntaxin 1, and Thy-1 of retinal ganglion cells (RGCs) isolated with the two-step immunopanning (TIP), two-step immunopanning-magnetic (TIPM), and flow cytometry (FC) methods. The Thy-1 levels in FC were the highest (p<0.05), and the syntaxin 1 levels were the lowest (p<0.05), while GFAP were zero. This indicates that the purity of the RGCs from FC is the highest, followed by TIPM, and the RGC purity of TIP is the lowest of the three methods. B: Relative mRNA levels of Thy-1, TUJ-1, Brn3b, syntaxin 1(syn), and GFAP from RGCs isolated with the FC method (high purity and low purity). There were no significant differences in the mRNA expression levels, except for GFAP. Data expressed as relative expression to the housekeeping gene β-actin. All relative RNA ratios expressed as the mean ± standard error of the mean (SEM; n = 9).