Figure 1From: Expression of target and reference genes in Daphnia magna exposed to ibuprofenPairwise variation of sequential normalisation factors ( NF n vs. NF n+1 ) estimated by geNorm. NF2 is based on the geometric mean of GAPDH and UBC; NF3 is NF2 and Act; NF4 is NF3 and WARS; NF5 is NF4 and SDH; NF6 is NF5 and TBP; NF7 is NF6 and 28S; NF8 is NF7 and 18S (gene name abbreviations as Table 1).Back to article page