Fig. 2. Models for recruitment of donors and pancreatic tissue for islet isolation and characterization.

Model 1 (top) relies on a single isolating centre obtaining whole pancreas organs or pancreatic fragments from donors for tissue processing. Enzymatic isolated islets, pancreatic tissue slices and sections or islet fragments obtained by laser capture microdissection are then distributed to individual laboratories, which independently perform assays in parallel, some of which may be duplicated. Data analysis is restricted to the assays performed by a single laboratory, leading to the generation and publication of complementary, or potentially overlapping datasets, which are then deposited in public databases post-publication. This approach, which prevailed until recently, offers the opportunity to integrate different datasets from different groups and verify the reproducibility of data, but also entails a greater risk for redundancy and it is not well suited in cases where a finite amount of pancreatic tissue is available, as in the case of surgical samples from living donors. Model 2 (bottom) follows a more centralized workflow, with multiple sites each being responsible for the recruitment of living and/or organ donors, their phenotyping, and the retrieval of the islets/islet fragments by enzymatic isolation, laser capture microdissection or the generation of pancreatic tissue slices/sections are carried out according to shared standardised operating procedures. Biological samples are further distributed to different laboratories, each well-qualified for the performance of a specific predefined assay. Collected clinical, laboratory and meta-data arising from the analysis are then jointly integrated and stored in a database accessible to all members of the network. Following their joint publication and deposition in public databases, data become available to the whole community. This figure was created with BioRender.com.