Fig. 2.

Relative quantification of chromosome 21-derived extracellular microRNAs in non-pregnant women, normal pregnancies and those bearing DS foetuses. Expression profile of chromosome 21-derived microRNAs in plasma samples was determined using comparative Ct method relative to normalization factor (geometric mean of ubiquitous invariable miR-16 and let-7d). The reference sample (euploid placental tissue) was used throughout the whole study to calculate 2^-(ΔΔCt) relative gene expression. *, extremes; ○, outliers.