Boxplots for reference sample CT distributions of the 761 genes at time points throughout the study. These boxplots show averaged expression values of all 761 genes over the duration of the study. The bottom edge of the box represents the 25th percentile of the data while the top edge of the boxplot represents the 75th percentile. The line inside the box represents the 50th percentile of the data or the median and the symbol + represents the mean. The distance between the 25th and 75th percentiles is defined as the Inter Quartile Range (IQR). A whisker extends from the upper edge of the box to the largest value that is inside a distance of 1.5*IQR. Similarly, a whisker extends from the lower edge of the box to the smallest values inside a distance of 1.5*IQR. Observations outside the fences of 1.5*IQR are marked by a square. The first boxplot represents data from the 3 assay repeats used to set a baseline, all other boxplots represent a single assay run. Overall, the CT distributions of the 761 genes assayed in the reference sample were stable throughout the study.