Related Experiment Video
Updated: Jun 21, 2026
Extracellular Glucose Depletion as an Indirect Measure of Glucose Uptake in Cells and Tissues Ex Vivo
Published on: April 6, 2022
Rapid blood separation is superior to fluoride for preventing in vitro reductions in measured blood glucose
1Department of Pathology, Stanford University, Stanford, California, USA. rzshi@stanford.edu
Aims:
To determine whether tubes containing sodium fluoride negatively bias blood glucose concentration by directly comparing glucose concentrations in paired blood samples collected in tubes containing lithium heparin (Li-Heparin) and tubes containing sodium fluoride/potassium oxalate (NaF-KOx).
Methods:
Paired blood samples from a group of patients (n = 1040) were collected in tubes containing Li-Heparin and tubes containing NaF-KOx at the same time. All Li-Heparin samples were centrifuged soon after collection and were kept cool in transport along with NaF-KOx samples, which were centrifuged at the receiving location after an average transport time of 4 h, but immediately before analysis. Glucose concentrations in the paired samples were determined simultaneously by an automated oxidase method.
Results:
The mean glucose concentrations for NaF-KOx samples and Li-Heparin samples were 5.7 mmol/l and 6.1 mmol/l, respectively, with a mean difference of 0.39 mmol/l.
Conclusion:
Rapid separation of heparinised blood is superior to fluoride alone for abrogating glycolytic effects on blood glucose measurements in the clinical laboratory.
