Total RNA was isolated from human post-mortem brain tissues (randomized for extraction) by the single-step method of RNA isolation using the miRNeasy 96 kit (Qiagen). All RNA extractions were performed by a single individual and, in the main, two sample plates were processed on each occasion (186 samples in a batch). The quality of total RNA was evaluated by the 2100 Bioanalyzer (Agilent) and RNA 6000 Nano Kit (Agilent). Total RNA samples were randomized across individuals and brain regions for processing for array analysis on 96-well plates, in large batches (four 96-well plates). All subsequent sample processing was performed on 96-well plates in the microarray facility (AROS Biotechnology, Denmark) within a specified timeframe. Processing with the Ambion WT Expression Kit and Affymetrix GeneChip Whole Transcript Sense Target Labeling Assay and hybridization to the Affymetrix Exon 1.0 ST arrays were performed in accordance with the manufacturers’ protocols. Hybridized arrays were scanned on an Affymetrix GeneChip Scanner 3000 7G and visually inspected for hybridization artifacts. Further details regarding RNA isolation, quality control and processing are reported in Trabzuni et al.24. There were a total of 1,231 arrays that pass quality control checks (Supplementary Table 1).
