Serum separator

To assess immune responses to (c)mRNA^hCFTR and pDNA^hCFTR, C57BL/6 (Jackson Laboratory (www.jax.org)) mice (n = 4 per group) were treated as described for Cftr^−/− mice. As positive controls a group of mice received two administrations of E. coli mRNA-NPs (20 µg) i.v. or i.t. C57BL/6 mice received two injections of 20 µg cmRNA^hCFTR complexed to NPs i.v. or i.t. After 6 h, 24 h, and 72 h of second injection mice were sacrificed and blood was collected. For cytokine measurement, blood from mice was used to obtain serum using a serum separator (www.sarstedt.com) and tested for IFN-α and TNF-α production as directed in the manufacturer’s instructions (www.thermofisher.com).

Blood samples in studies performed at the hospital of Halland were taken at birth (umbilical cord blood), at 48‐96 hours in conjunction with the metabolic screening, at 4 months and at 12 months. For the children born in Halland, blood was collected in tubes with serum separator (BD Vacutainer, Plymouth, UK). Blood samples in the study carried out at Karolinska University Hospital were taken at birth (umbilical cord blood) and at 4 months and blood was collected in serum tubes with serum separator (Sarstedt AG & Co, Nümbrecht, Germany).
Blood sampling (a maximum of 2.5 mL blood) was at 4 and 12 months performed after application of a local dermal analgesia with lidocaine 2.5% and prilocaine 2.5% (EMLA, AstraZeneca).