Fig. 2.

Yield, quality and purity of extracted RNA (mean ± SD). Three different treatment groups, n = 4, (SF-snap frozen, HS-heat stabilized, HS + 12 h-heat stabilized with 12 h incubation at room temperature after heat stabilization), extracted with two different protocols (Q-QiaZol buffer and U + Q-Urea pre-solubilization prior to QiaZol extraction) were compared. μg RNA/mg tissue-yield of RNA from samples (left scale), RIN-RNA quality score as measured using the bioanalyzer (left scale), A260/A280-assesment of protein contamination (right scale), A260/A230-assesment of contaminants such as guanidine thiocynate and carbohydrates (right scale). *p < 0.05, **p < 0.01, ***p < 0.001 compared with snap frozen samples (SF) within respective extraction protocol, ^#p < 0.05, compared to corresponding group in non-urea pre-solubilized samples (ANOVA followed by Tukey HSD test; n = 4).