Real-time quantitative RT-PCR analysis of murine VEGF gene expression in tumors. (A) Melting curve analysis of the VEGF and GAPDH amplicons. Distinct melting curves of VEGF (dotted line) and GAPDH (solid line) are shown together with controls. (B) Relative efficiency plot of VEGF and GAPDH. The ΔC_T (difference in C_T values of VEGF and GAPDH) were calculated for each cDNA dilution. (C) Murine VEGF gene expression levels in MT-1080, QT-1080, and WT-1080 tumor samples. Mouse liver RNA (black bar) was used as a positive control. Each column represents the average of 3 amplification reactions (error bars represent standard deviation) performed on a single cDNA sample reverse-transcribed from RNA derived from each tumor sample. Samples MT-2T, MT-3T, and MT-6T are representative MT-1080 tumors (white bars). Samples WT-3T, WT-5T, and WT-11T are representative WT-1080 tumors (dark grey bars), while samples QT-1T, QT-5T, and QT-7T are representative QT-1080 tumors (light gray bars). (D) Agarose gel analyses of PCR products obtained following specific amplification of murine VEGF (top) and murine GAPDH (bottom) amplicons. ^* indicates negative controls lacking reverse transcriptase in first-strand cDNA synthesis.