Figure 11. Reverse transcriptase polymerase chain reaction amplification of transcription response element mRNAs during ARPE-19 retinal pigment epithelium cell differentiation RNA was isolated from undifferentiated and differentiated ARPE-19 cells and subjected to RT–PCR analysis to detected transcription response element (TRE) mRNAs as described in Methods. In A, all reactions were performed for 40 cycles, where lane 1 represents DNA standards, lane 15 represents the positive control primers for GADPH, and lane 16 is the negative control with no mRNA template. The intervening lanes in A represent primers specific for the following TFs: 2 Core binding factor, 3 E2F1, 4 Evi-1, 5 GATA1, 6 HNF-1, 7 IRF-1, 8 Nkx2–5, 9 NKX3A, 10 Oct-1, 11 SMAD3, 12 SREBP-1, 13 TFE3, 14 v-Myb. In B, semi-quantitative RT–PCR was also done for either 30, 35, or 40 cycles as indicated using primers specific for GATA-1, IRF-1, or SMAD3. The first lane in A represents a standard DNA ladder at 300, 400, and 500 bp, while in B the DNA standards are at 400 and 500 bp.