Pre-analytical stability of haematinics, lactate dehydrogenase and phosphate in whole blood at room temperature up to 24 h, and refrigerated serum stability of lactate dehydrogenase, folate and vitamin B12 up to 72 h using the CRESS checklist.
Author(s): Williams R, Jankute M, Ifrahim R, Cordle J, Hepburn S
Publication: Clin Chem Lab Med, 2024, Vol. , Page
PubMed ID: 39609111 PubMed Review Paper? No
Purpose of Paper
This paper compared the stability of lactate dehydrogenase (LDH), folate, vitamin B12, iron, and phosphate levels in whole blood that was stored at room temperature for up to 24 h and in serum that was refrigerated for up to 72 h.
Conclusion of Paper
The authors report that serum hemolysis, icterus and lipemia remained within acceptable limits for all specimens. When whole blood was stored at room temperature, mean changes that exceeded the maximum permissible instability (MPI) were observed for LDH after 7 h, folate at 12 h, and phosphate at all time points examined, but all other analytes remained within the MPI. Interestingly, phosphate levels initially declined with room temperature storage of blood in all nine specimens, but increased after 12 h . While the mean change in iron levels remained within the MPI, the 95% confidence limits for the mean change fell outside the MPI when blood was stored at room temperature for 24 h. None of the analytes were significantly affected by storage of serum at 4-8°C for up to 72 h.
Studies
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Study Purpose
This study compared the stability of LDH, folate, vitamin B12, iron, and phosphate levels in whole blood that was stored at room temperature for up to 24 h and in serum that was refrigerated for up to 72 h. Blood was collected from 10 volunteers into five Starstedt serum tubes. Unless otherwise specified, specimens were stored upright for 30 min (for clot formation) before serum separation by centrifugation at 2000 g for 7 min. Serum was aliquoted into Sarstedt False Bottom Tubes and immediately analyzed (only one control) or stored at -20°C for 13 days (all experimental specimens) until analysis. To investigate effects associated with blood storage, matched tubes were stored for 0, 7, 8, 12, and 24 h at room temperature (15-25°C) before serum separation. To investigate effects associated with serum storage, serum in Sarstedt False Bottom Tubes was stored at 4-8°C for 0, 7, 12, 24, 48 and 72 h. Serum was thawed on a tube roller for 20-30 min and levels of LDH, folate, vitamin B12, iron and phosphate were quantified using a Roche automated track system. Maximum permissible instability (MPI) was calculated based on within-subject biological variation (CVI) and between-subject variability and was defined as 4.7% for LDH, 9.8% for folate, 7.7% for ferritin, 14.1% for vitamin B12, 14.4% for iron and 4.9% for phosphate.
Summary of Findings:
One specimen was excluded due to extreme variability, leaving nine for the remaining analysis. The authors report that serum hemolysis, icterus and lipemia remained within acceptable limits for all specimens. When whole blood was stored at room temperature, mean changes that exceeded MPI were observed for LHD after 7 h, folate at 12 h, and phosphate at all time points evaluated, but all other analytes remained within the MPI. Interestingly, phosphate levels initially declined with room temperature storage of blood in all nine specimens but then increased after 12 h. While the mean change in iron levels remained within the MPI, the 95% confidence limits for the mean change fell outside the MPI when blood was stored at room temperature for 24 h. None of the analytes were significantly affected by storage of serum at 4-8°C.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Electrolyte/Metal Clinical chemistry/auto analyzer Small molecule Clinical chemistry/auto analyzer Protein Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Centrifugation Centrifugation delays investigated
Storage Storage duration 0 h
7 h
8 h
12 h
24 h
48 h
72 h
Storage Storage temperature Room temperature as blood
4-8°C as serum
Storage Storage conditions As blood
As serum