The GTEx pilot biospecimen collection included up to 41 different PAXgene preserved postmortem target tissue types (Fig. 4). The PAXgene Tissue preservation system9 developed by Qiagen was selected for GTEx because it facilitates good histological analysis as well as extraction of high-quality RNA and DNA. Hair, whole brain (frozen), and sections from 11 brain sub-regions (frozen) were also collected. The tissue types collected for GTEx were chosen based on their relevance to the scientific goals of the project, their clinical significance, logistical feasibility, and their relevance to the research community. Recovering target tissues from donors in rapid autopsy programs, where the donors were not donating tissue for transplant purposes, was frequently achievable. The OPO setting proved to be more challenging due to several factors, including the need to prioritize tissue and organ donations to living recipients and delays due to cause-of-death investigations; however this obstacle did not hinder GTEx from reaching its collection goal, ultimately procuring 10,152 PAXgene preserved tissue aliquots from190 donors.
