Figure 5. Relative mRNA expression of EphA2, EphA3, ephrinA1 and ephrinA5 in irradiated (10 Gy, 1 d and 7 d after X-ray) melanoma cells analyzed by quantitative real-time RT-PCR. Total RNA was extracted, followed by DNase digestion. Fifty nanograms of the pretreated RNA was applied into each RT-PCR reaction. mRNA levels of Eph and ephrins were determined using the delta-delta CT method with 18SrRNA as reference. Relative expression is depicted in relation to untreated cells. For each cell line three independent RNA samples were analyzed, each in triplicate. Symbols represent means ± SEM, (p ≤ 0.05), *, vs. 0 Gy, ANOVA, Bonferroni post hoc method.