Impact of Delayed Biospecimen Processing on Serum Proteomics in Samples from a Parabolic Flight

Abstract In-flight blood collection during spaceflight is limited by both the constraints of available collection methods and the inability to process samples immediately. To bridge this gap, ezdraw, a blood self-collection device was used aboard a parabolic flight. Furthermore, to mimic operational constraints, blood samples were stored at room temperature with delayed processing, and serum was extracted at 24 and 48h. Protein stability was analyzed using the Olink Explore HT platform, profiling up to 5,400 proteins. Of the 3,201 detectable proteins, 2,789 (87%) proteins remained stable at 24h and 2,731 (85%) at 48h, showing resilience to delayed processing. Key proteins involved in signaling immune related and metabolic pathway remained stable. Unstable proteins did not significantly impact representation of the major biochemical pathways. These findings suggest most serum proteins remain robust to delayed processing, supporting the feasibility of in-flight blood collections and their use for molecular profiling as demonstrated here.