Cancer Diagnosis Program | Biorepositories and Biospecimen Research Branch

Search BRD Papers

Five days serum glucose stability at room-temperature in centrifuged fast-clotting serum tubes and the comparability with glucose in heparin-plasma and plasma containing citrate-stabilizer.

Author(s): Bakkebø H, Haaland KL, Hoff KS, Schwettmann L

Publication: Scand J Clin Lab Invest, 2024, Vol. 84, Page 62-67

PubMed ID: 38451167 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   This study compared glucose levels of lithium heparin plasma with levels of sodium fluoride, EDTA, and citrate buffer (NaF–EDTA–citrate) plasma, and serum from serum separator tubes (SST) and fast-clotting tubes. Glucose levels were also compared in serum (from both tube types) and NaF-EDTA-citrate plasma specimens that were stored for up to 72 h in the dark at 20-22°C before analysis. Blood was collected from thirty volunteers (no diagnosis specified) into serum separator tubes, fast-clotting serum tubes, lithium-heparin tubes, and NaF–EDTA–citrate tubes. Lithium heparin tubes were stored in an ice-water slurry for transport to the laboratory (10 min), while all other tubes were stored at room temperature. Serum was isolated from fast-clotting tubes after 10 min and from serum separator tubes after 30 min. Plasma was isolated from lithium heparin tubes after 10 min (in ice slurry) and from NaF–EDTA–citrate tubes after 20 min. Both serum and plasma were separated by centrifugation at 1,800 g for 10 min at 20-22°C. Glucose levels were quantified in serum and plasma immediately after separation and again after storage in the dark at 20-22°C for 24, 48, 72, 96 and 120 h. At each timepoint, plasma/serum was mixed by inversion five times and glucose was quantified using a Roche Cobas c702 analyzer. Based on the biological variation, the clinical acceptance limit for bias was defined as ±2.4% and the total allowable error as ±6.5%.

   Summary of Findings:

   Compared to lithium heparin plasma (control), NaF-EDTA-citrate plasma had significantly higher glucose levels (5.47 versus 5.23, P<0.01), and serum from SST or fast clotting tubes had significantly lower glucose levels (5.23 versus 5.09 and 5.24, respectively; P<0.01, both). Importantly, the bias in glucose levels in NaF-EDTA-citrate plasma and SST serum exceeded the clinical acceptability threshold (4.7% and -2.6%, respectively). In contrast, the bias in glucose levels in fast clotting serum relative to lithium heparin plasma was very small, which led the authors to conclude that fast clotting serum is an acceptable alternative to lithium heparin plasma. Significant declines in glucose with storage in the dark at 20-22°C were noted in serum from SST or fast clotting tubes (P=0.034, and P=0.011) and in NaF-EDTA-citrate plasma (P=0.008). However, pairwise comparisons only found a significant difference in glucose levels (P<0.05) from the 0 h timepoint in NaF-EDTA-citrate plasma that was stored for 24 h and SST serum that was stored for 72 h. Importantly, bias remained <2.4% and glucose concentration remained within 6.5% of the 0 h specimen for all timepoints and for all tube types investigated.

   Biospecimens

   • Bodily Fluid - Serum
   • Bodily Fluid - Blood
   • Bodily Fluid - Plasma

   Preservative Types

   • None (Fresh)

   Diagnoses:

   • Normal

   Platform:

   Analyte	Technology Platform
   Carbohydrate	Clinical chemistry/auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Type of collection container/solution	Lithium heparin Vacuette tube NaF-EDTA-Citrate Vacuette tube Fast-clotting serum tubes Serum separator tubes
   Biospecimen Acquisition	Anticoagulant	Citrate/sodium fluoride EDTA Lithium heparin None
   Biospecimen Aliquots and Components	Blood and blood products	Plasma Serum
   Storage	Time at room temperature	0 h 24 h 48 h 72 h 96 h 120 h

   View more