Figure 9. Western blot analysis of retinal progenitor cell (RPCs) cultured with either epidermal growth factor (EGF) or EGF+GDNF for 5 days. A: Anti-nestin identified two distinct protein bands with anticipated molecular weights of approximately 220 kDa and approximately 200 kDa. Two bands were also identified by anti-K_i-67 with molecular weights approximately 395 kDa and approximately 345 kDa consistent with the molecular weights of alternatively spliced K_i-67 isoforms [31]. Lane a: nestin in EGF; lane b: nestin in EGF+GDNF; lane c: K_i-67 in EGF; lane d: K_i-67 in EGF+GDNF. β-actin was used as the loading control (lower panels). B: Quantitative analysis showed no significant difference in nestin expression between treatment conditions. For K_i-67, there was a statistically significant increase in total protein expression for the EGF+GDNF condition of 1.18±0.009 fold (*p<0.02).