Figure 4
From: Straightforward and sensitive RT-qPCR based gene expression analysis of FFPE samples
Effect of preamplification on qPCR quantification cycle difference (∆Cq) and qPCR sensitivity.
∆Cq is calculated as difference in Cq values between any two cell lines from four tested cell lines and 48 genes (totaling 6 × 48 data points). (a) ∆Cq Pearson correlation between preamplified and non-preamplified fresh frozen (FF) samples. (b) ∆Cq Pearson correlation between preamplified and non-preamplified cell pellet FFPE samples. (c) ∆Cq Pearson correlation between preamplified cell pellet FFPE samples and non-preamplified FF cell line samples. (d) Cq Pearson correlation between preamplified and non-preamplified samples from cell pellet FFPE samples. Cq values are shown for 4 cell lines and 48 genes, hence 4 × 48 data points were used in the correlation plot. Dots marked in red represent genes detected in preamplified samples only. No qPCR signal is observed for these genes in non-preamplified samples. For visualization purposes, undetected signal was replaced by a Cq value of 35.
