Figure 6. Effect of insulin-based culture supplement on HIOMT and red opsin gene regulation

The effect of an insulin-based culture supplement on HIOMT and red opsin gene regulation was assessed. Total RNA (15 μg per lane) extracted from approximately 10⁷ cells was analyzed on northern blot with the indicated ³²P-labeled cDNA probes. 18S rRNA BrEt-induced fluorescence was used to verify equal RNA loading in the lanes. A: Duplicate cultures of E7 retinal cells were kept for 2 days in medium supplemented with either insulin-transferrin-selenium (ITS) or newborn calf serum (NCS). Two batches of cells cultured for two days in ITS-supplemented medium were transferred to NCS-supplemented medium for two additional days. B: E7 retinal cells were cultured for three days in medium containing each component of the ITS supplement, as indicated (insulin 1.5 μM, selenium 38 nM, transferrin 69 nM).