Figure 5From: Normalization with genes encoding ribosomal proteins but not GAPDH provides an accurate quantification of gene expressions in neuronal differentiation of PC12 cellsFold changes in target gene expressions normalized using different reference gene(s). Fold changes in transcript expressions of Egr-1 (A), Integrin alpha 1, ITGA1 (B), Crystallin alpha b, CRYAB (C), in NGF treated samples relative to that of control were normalized by (1) geometric mean of RPL10a/RPL29; (2) geometric mean of RPL19/RPL29; (3) ACTB or (4) GAPDH. Normalization by GAPDH led to significant quantitative underestimations of EGR1 and ITGA1 upregulation and overestimation of CRYAB downregulation. Dotted line represents the 2-fold difference between treatment and control subjects, a cut off commonly used to distinguish significant changes from insignificant ones. Significant differences between fold changes normalized by various reference gene(s) were calculated using the paired Student's t-test. A value of p < 0.05 was considered significant (**p < 0.01; *p < 0.05).Back to article page