Investigation of the preanalytical stability of blood donor samples

BACKGROUND: Centralization of blood donor screening and implementation of fully automated testing platforms have increased sample transport distances. Although transport is usually performed under controlled conditions (2-8°C), temperature excursions may occur. This study investigated the impact of such deviations on blood donor screening using a controlled preanalytical approach. STUDY DESIGN AND METHODS: Whole blood samples (EDTA-K3, citrate plasma, and serum tubes) were collected from 10 regular plasma donors per temperature condition (n = 30) and stored at 4, 22, or -10°C. To assess the impact of temperature excursions on analytical sensitivity, samples were supplemented with positive material representing low-level analytes relevant for blood donor screening, including infectious serology and quantitative parameters. Samples were analyzed for key transfusion-relevant markers for up to 8 days post-collection using CE-certified automated systems from Roche, Beckman Coulter, and Werfen. RESULTS: Both qualitative (infectious serology, nucleic acid amplification testing, blood group) and quantitative parameters (e.g., immunoglobulin G and total protein) remained stable across all temperatures and time points. Analytical sensitivity and specificity for blood donor screening assays were consistently 100%. DISCUSSION: High analytical stability was demonstrated across a broad temperature range (-10 to 22°C), simulating extreme transport conditions. Reliable blood donor screening was achievable even after up to 8 days of storage without immediate centrifugation. These findings suggest that moderate temperature excursions during transport may not compromise screening results and that extending acceptable preanalytical conditions could optimize logistics, reduce sample discard, and support continuous availability of safe blood products.