Figure 1

Selection of candidate reference genes. Expression levels of probe sets for genes with one or more probe sets among the top 20 most stable and abundantly expressed across all samples, identified from screening publicly available Affymetrix gene expression profiles of left ventricle myocardium from 195 heart transplant recipients and 16 unmatched heart donors [11] (GEO accession GSE5406, http://www.ncbi.nlm.nih.gov). GAPDH, RPL22, RPS4X, TPT1, RPL23A, RPL41 and SRP14 genes were selected as candidate reference genes (shown in red), based on their high abundance and consistent expression across the majority of probe sets. Affymetrix probe set nomenclature is preceded by the gene symbol. Boxes indicate median and interquartile range, whisker length is 150% of the interquartile range. Observations beyond the whiskers are denoted by open circles.