Evaluation of UNI-VAC serum separator, ethylenediaminetetraacetic acid, sodium citrate, and sodium fluoride tubes: A comparison with Becton, Dickinson and Company Vacutainer tubes

Errors in the preanalytical phase are influenced by several factors, including blood collection tubes. Labex, Inc. has developed UNI-VAC tubes using a separation gel formulated with fatty acid acrylamide to enhance stability. We aimed to compare the performance of the UNI-VAC tubes with Becton, Dickinson and Company Vacutainer tubes for 53 analytes. Forty adult outpatients were prospectively enrolled in the comparison study, and an additional 20 participants were included to evaluate lot-to-lot variability. Four UNI-VAC tube types (serum separator, ethylenediaminetetraacetic acid [EDTA], sodium citrate, and sodium fluoride) were compared with their Vacutainer counterparts. Comparative performance was evaluated using Passing–Bablok regression and bias criteria from the European Federation of Clinical Chemistry and Laboratory Medicine Biological Variation Database and Westgard specifications. Stability was assessed for EDTA tubes at 24 h and sodium fluoride tubes at 24–72 h (4°C storage). The lot-to-lot variability of the EDTA tubes was examined across the three UNI-VAC and two Vacutainer lots. Fifty (94%) analytes met the predefined acceptability criteria. Lactate dehydrogenase (−4.3%), mean corpuscular volume (1.5%), and mean corpuscular hemoglobin concentration (−1.0%) marginally exceeded these limits, although the differences were small and unlikely to be clinically significant. No visible gel instability or other visible tube-related issues were observed. EDTA tubes demonstrated stability after 24 h, although the basophil percentages and platelet indices showed reduced consistency. Glucose values were stable for up to 48 h but declined at 72 h in both tubes. The lot-to-lot variability of the UNI-VAC EDTA tubes was comparable to that of the Vacutainer tubes. UNI-VAC tubes show a clinical performance equivalent to that of Vacutainer tubes for most analytes, with acceptable stability. These findings indicate that UNI-VAC tubes represent a reliable alternative for clinical laboratory use, with further validation in larger patient cohorts.