Figure 2
RT-qPCR reference gene selection for Pseudomonas donghuensis P482. (a) Boxplot representing the distribution of Cq (threshold cycle) data among the tested potential reference genes. The plot was calculated from raw data consisting of technical replicates’ mean Cq for each sample. The band in the box represents the median value, the top edge of the box is the upper quartile (Q3) while the bottom edge of the box is the lower quartile (Q1). Q3 and Q1 referred to the 75th percentile and the 25th percentile, respectively, meaning that 75 or 25% of the data were at or below the point. The whiskers represent the maximum and minimal values excluding outliers. Outlier data is presented with black diamond symbol (♦). (b) RefFinder comprehensive stability value (CSV) calculated as a geometric mean of the ranks assigned to the tested RGs by algorithms comprising RefFinder tool. The lower the CSV, the more stable the expression of a given gene. (c) qbase + geNorm RG stability analysis. Average expression stability of tested RGs obtained with geNorm algorithm shown as geNorm M value. The lower the M value, the more stable the gene expression. (d) Determination of the optimal number of reference targets shown as qbase + geNorm V chart for the tested reference targets. Analysis shows no significant difference in experimental situation when comparing the use of 3 or 4 reference genes (geNorm V < 0.15 for V3/4), meaning 3 reference genes are sufficient for expression normalisation.
