Comparison of gene expression ratios reported by the Affymetrix GeneChip® Vitis oligonucleotide microarray and by quantitative real-time RT-PCR. Data were from 19 probesets and three different tissues (pulp, skin and seed) from well-watered vines including comparisons from two probesets and two tissues (pulp and skin) between well-watered and water-deficit stressed vines. The microarray log2 (expression ratio) values (y-axis) are plotted against the log2 (expression ratio) obtained by quantitative real-time RT-PCR (x-axis). A) Comparisons between pulp and skin. B) Comparisons between pulp and seed. Linear regression analysis showed an overall coefficient of variation of 0.93 and 0.94, respectively (formula insets).