Figure 3. Candidate reference gene expression in neonatal rat retinal cDNA pools

Expression of each reference gene was determined relative to the expression of the same gene in the pooled standard sample. Non-normalized expression values are shown for acidic ribosomal phosphoprotein (ARBP; A), hypoxanthine guanine phosphoribosyltransferase (HPRT; B), and RNA polymerase 2 (RNAP2; C). The average variation in relative expression between each pair of genes within each of the six cDNA test samples was used to assess stability of gene expression. The relative expression values for ARBP and HPRT were more closely correlated than were those for either gene with RNAP2. RNAP2 showed the lowest expression stability. In the figure n=6 replicates per experimental group of three pooled rat retinas and error bars represent ±SD. The following abbreviations were used: Sprague Dawley (S), Fischer 344 (F), Dark Agouti (D), room air raised, day 14 (R14), and cyclic hyperoxia exposed, day 14 (O14).