Figure 1
From: The limits of log-ratios
R-I plots for microarray expression data exhibit the limits of log-ratio measurements obtained on arrays. As the measured intensity on the arrays approaches its upper and lower limits, the dynamic range for accurately estimating fold-change measurements is also limited. Shown here are R-I plots for three different data sets showing the entire range (A,C,E) and a close-up of the upper end of the end of the effective range for array measurements (respectively B,D,F). The diamond-shape delimits the range of measurements obtainable on microarrays.