Purified total RNA was amplified using the Agilent Low-Input QuickAmp Kit (Agilent, Waldbronn, Germany).
Hybridization protocol
Hybridization was performed following the Agilent protocol at 65°C over-night in an in-situ hybridization oven with slides mounted in Agilent hybridization chambers. Slides were rotated with 2 rpm.
Scan protocol
Slides were scanned using the InnoScan 900 scanner (Innopsys, Carbonne France) at 2 µm/pixel resolution and analyzed with Mapix 8.5.0
Data processing
Raw data was further processed using R (http://www.R-project.org) and limma (Ritchie, M.E., Phipson, B., Wu, D., Hu, Y., Law, C.W., Shi, W., and Smyth, G.K. (2015). limma powers differential expression analyses for RNA-sequencing and microarray studies. NAR 43(7), e47). Background correction was performed with the normexp model using negative control spots and and offset of 1. Spot intensities were quantile normalized between arrays.