Linear range of detection on microarray and RT-qPCR platforms. Example plots of modelling the linear range of each gene expression platform are displayed. Normalised signal intensities (microarrays) (symbol: black diamond) or ΔCt values (RT-qPCR) (symbol: grey triangle) are plotted against the standard (copy number/ng). Individual data points for ERCC-13 from three independent experiments are plotted. Correlation analysis was performed over the linear portion of the detection range (Microarrays: 10-105 copies/ng; RT-qPCR 10 - 106 copies/ng) and Pearson correlation coefficient (R2) values are displayed (microarray value in bold).