Background Translational research driven by large-scale biological testing requires significant volumes of blood for research testing. However, blood is also required for clinical management of research subjects, which must take priority. Paradoxically, much of the blood drawn for clinical management goes unused. Here, we present our approach for retrieving unused blood samples collected for clinical management and recycling them for research purposes.

Methods Clinical Blood samples were collected for 60 days during a 61-day xenotransplantation experiment in a brain-dead decedent. Twice weekly, research staff went to the chemistry and hematology laboratories and collected stored blood, serum, and plasma samples that were >12 hours old. Sample collection and storage before retrieval was per standard clinical protocols. Samples were de-identified and relabeled and brought to a central biorepository for processing and storage. The quantity of plasma, serum, red blood cells (RBCs), and peripheral blood mononuclear cells (PBMCs) collected from clinical labs and bespoke research blood draws were compared.

Results Unused blood from clinical samples yielded a minimum of 6.0 ml per day of plasma, representing 62% of all plasma obtained. Serum was only recoverable on 13 days (22%), with a mean 2.3 ml collected on those days, representing 8% of all serum obtained. PBMCs were only recoverable on six days (10%).

Conclusions Overdrawn clinical laboratory samples represent an untapped resource of blood samples for research and can help augment samples collected explicitly for research purposes. With careful planning, this represents an opportunity to minimize iatrogenic blood loss in clinical-translational research.

Robert A. Montgomery has received research funds from Lung Biotechnology, a wholly owned subsidiary of United Therapeutics Corp. He serves on the advisory board of eGenesis and has been a strategic advisor for Recombinetics. All other authors report no potential conflicts of interest.

This study did not receive any direct funding. This study used resources from the NYU Langone Health Center for Biospecimen Research and Development (CBRD), Histology and Immunohistochemistry Laboratory (RRID:SCR_018304), supported in part by the Laura and Isaac Perlmutter Cancer Center Support Grant (NIH/NCI P30CA016087). Ian S. Jaffe was supported by the National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, through Grant Award Number UL1TR001445. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

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The Research on Decedents Oversight Committee of New York University gave ethical approval for this work.

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