Technical noteThe importance of selecting the right internal control gene to study the effects of antenatal glucocorticoid administration in human placenta

- RT-qPCR requires a suitable set of internal control genes for an accurate normalization.
- The main effect of antenatal glucocorticoid treatment, gestational age at birth and sex on raw or normalized RT-qPCR was assessed in placenta.
- Different algorithms (geNorm, BestKeeper, NormFinder) were compared for selecting an appropriate set of internal control genes.
- Reliable normalization was achieved using the geometrical mean of PPIA, RPL19, HMBS and SDHA accounting for antenatal betamethasone treatment, gestational age and sex.

RT-qPCR requires a suitable set of internal control genes (ICGs) for an accurate normalization. The usefulness of 7 previously published ICGs in the human placenta was analyzed according to the effects of betamethasone treatment, sex and fetal age. Raw RT-qPCR data of the ICGs were evaluated using published algorithms. The algorithms revealed that a reliable normalization was achieved using the geometrical mean of PPIA, RPL19, HMBS and SDHA. The use of a different subset ICGs out of the 7 investigated, although not statistically affected by the conditions, biased the results, as demonstrated through changes in expression of glucocorticoid receptor (NR3C1) mRNA as a target gene.