Figure 4

The effect of suboptimal blood volume collected in the Tempus tubes on RNA quality and transcript stability. A) Cord blood collected in Tempus tubes from maternity units in a period of one year (n = 10 853). B) The effects of suboptimal volume of adult blood collected in the Tempus tubes on relative transcript level for six genes. Adult blood from one healthy donor was collected in Tempus tubes (n = 18). The following blood volumes (3.0, 2.5, 2.0, 1.5, 1.0 and 0.5 ml) were collected in the Tempus tubes (n = 3; three parallels tubes for each blood volume). C) The effects of suboptimal volume of cord blood collected in the Tempus tubes on relative transcript level for six genes. Cord blood from one donor was collected in Tempus tubes (n = 10). The following blood volumes (3.3, 3.0, 2.0, 1.0, and 0.5 ml) were collected in the Tempus tubes (n = 2; two parallels tubes for each blood volume). Samples with 3 ml blood per tube were used as reference samples; hence all other samples were compared against the reference samples. Each bar represents the average log2-transformed fold change values and the error bar indicates = SE. Since some of the samples had low RNA quality, selecting stably expressed reference genes for normalization was a challenge. We therefore used the average Cq value for each gene to normalize the samples: ΔCq (sample) = Cq (gene) – Cq (average); these values where converted into linear scale, 2^-ΔCq. Fold changes were calculated by dividing ΔCq value of the sample by the ΔCq value of the reference sample.