Pilot study from FFPE brains of the Danish Brain Collection
Neurological disorders impose substantial morbidity and disability, yet their biological underpinnings remain incompletely understood, in part due to limited access to human brain tissue for genetic and molecular investigation. The Danish Brain Collection, which contains preserved brains from individuals who lived in Danish psychiatric institutions from the 1940s to the 1980s, offers a unique opportunity to investigate these pathologies using archived material at the molecular level. We have evaluated the feasibility of extracting and sequencing both DNA and RNA from such an invaluable set of decades-old archival FFPE brain samples. We describe how different DNA and RNA extraction methods influence nucleic acid yield and quality, and that RNA end-repair prior to library preparation enhances transcript diversity, improving transcriptomic data quality from such aged FFPE brain samples. Moreover, we characterize biologically informative bulk transcriptomic sequencing data using protein-coding and microRNA loci, revealing tissue-specific gene expression profiles.