Quality assessment from biobank plasma and serum specimens: a systematic review.

Accurate assessment of serum and plasma quality is essential for reliable biobanking and research. This systematic review synthesizes 46 studies and shows that current evaluation methods prioritize sample processing delays, freeze-thaw cycles, storage duration, and temperature variations, while neglecting preanalytical factors like medication and diet. Temperature critically affected stability: non-refrigerated samples (8-37 °C) showed 3.2 times more biomarker alterations than refrigerated samples after >24 h delays. Freeze-thaw cycles caused dose-dependent instability, with >10 cycles triggering severe degradation (70% altered biomarkers) and universal enzyme impairment. Even ≤5 cycles significantly altered enzymes (43% affected). Enzymes also degraded over time at <-20 °C, with alteration rates rising from 20% (1-5 years) to 55% (>10 years). The analysis consolidates stability data for enzymes, sterols, cytokines, and metabolites across conditions, providing an evidence-based foundation for quality control. Standardizing procedures to address these gaps will enhance sample integrity, research reliability, and clinical utility. Critically, this review underscores that preexisting biobank collections may have inherent limitations, necessitating careful evaluation of sample history when designing studies.