Reproducibility of metabolic signatures in blood unit segments versus transfusates

Background The implementation of metabolomics‐based quality assessment of stored red blood cells (RBCs) has been limited by logistical constraints and the need for sterile, scalable sampling strategies. Sampling RBC segments, routinely used for compatibility testing, offers a practical alternative to direct unit interrogation, but the biochemical equivalence of segments and transfusates has not been systematically evaluated. Study Design and Methods We performed semi‐targeted metabolomics on 51 paired segments and transfusates collected immediately after transfusion to determine concordance across sampling sources. Results and Discussion Of the 250 metabolites detected in both matrices, approximately 70% showed significant positive correlations, spanning glycolytic, redox, lipid, and nucleotide pathways previously implicated in the RBC storage lesion. The top correlated metabolites displayed strong linear relationships independent of storage duration, confirming that segments reliably capture unit‐level metabolic phenotypes. These results support the utility of segment‐based omics profiling as a scalable, minimally disruptive approach for next‐generation precision transfusion medicine.