Peter van Mourik

125 Centralized intestinal organoid generation this procedure. Ultimately, since both procedures were found to be safe, the choice of biopsy device should be based on the target population and the experience and preference of the operator. Several examples of organoid biobanks exist, with success rates of organoid establishment ranging from ~60 – 90% 2,15,16 . However, these biobanks were generated from locally obtained samples. Shipment of live tissue samples over large distances requiring several days of transportation was considered to limit the organoid establishment rates. Here we show that standardized working instructions can lead to high success rates in a multicenter setting with extensive transport times of up to 72 hours. The low failure rate of samples processed between 48 and 72 hours after collection suggests that even longer transport times might be feasible. Whether these results can be extrapolated to other organoid models needs to be further investigated. Interestingly, only 8 samples failed due to sample contamination. Considering, the rectal biopsy procedure and transportation, this demonstrates that the combination of the standardized procedure, media conditions, and transportation allow for efficient collection of clean samples. In this international, multicentre study, establishment of intestinal organoids from both rectal suction and forceps biopsies was highly successful. These data implicate that international biobanks can be effectively generated through shipment of fresh samples to a central laboratory and support the implementation of these procedures for research and future clinical indications. 5