Stability of serum, plasma and urine osmolality in different storage conditions: Relevance of temperature and centrifugation.
Author(s): Sureda-Vives M, Morell-Garcia D, Rubio-Alaejos A, Valiña L, Robles J, Bauça JM
Publication: Clin Biochem, 2017, Vol. 50, Page 772-6
PubMed ID: 28372954 PubMed Review Paper? No
Purpose of Paper
This paper investigated the effects of pre- and post-centrifugation storage temperature and duration on the stability of osmolality of plasma, serum, and urine based on three sets of guidelines.
Conclusion of Paper
Osmolality of serum and plasma increased over the storage duration with larger changes observed when stored at room temperature than at 4˚C and osmolality increased when stored as uncentrifuged blood rather than plasma and during the first 6 days when stored as uncentrifuged blood instead of serum. Urine osmolality was stable for 14 days at -21˚C but increased with storage at 4˚C or room temperature. The stability thresholds were longer when using the SEQC-ML and Westgaard guidelines than the WHO recommendations for serum and room temperature stored urine but were shorter for refrigerated urine.
Studies
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Study Purpose
This study investigated the effects of pre- and post-centrifugation storage temperature and duration on the stability of osmolality of plasma and serum using three sets of guidelines. Blood from 50 fasting adults was collected by venipuncture into four SST-II or lithium-heparin tubes. Two tubes of blood were immediately aliquoted; stored at room temperature and 4˚C for 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, and 14 days; and then centrifuged at 2000x g for 10 min before assay while the other two were stored for 30 min at room temperature, centrifuged at 2000x g for 10 min, and then stored at room temperature and 4˚C for 1, 2, 3, 4, 5, 6, 7, 10, 11, 12 and 14 days prior to analysis.
Summary of Findings:
Osmolality of serum increased over the storage duration with larger changes observed when stored at room temperature than at 4˚C and during the first 6 days when stored uncentrifuged. Serum osmolality was affected by storage of uncentrifuged blood with a procoagulant for as little as 24 h at room temperature by SEQC-ML and Westgaard guidelines but was stable for 2 days at room temperature by the RCPA-QAP guidelines and more than 14 days at 4˚C by all three sets of guidelines. Osmolality of serum stored at room temperature after centrifugation was stable for 4 days (SEQC-ML and Westgaard guidelines) or 6 days (RCPA-QAP guidelines) and when stored at 4˚C for 8 days (all three sets of guidelines).
Osmolality of plasma increased over the storage duration with larger changes observed when stored at room temperature than at 4˚C and when stored uncentrifuged. Plasma osmolality was stable when uncentrifuged lithium-heparin anticoagulated blood was stored at room temperature for 3 (Westgaard guidelines), 4 (SEQC-ML guidelines), or 5 days (RCPA-QAP guidelines) or stored at 4˚C more than 14 days by all three sets of guidelines. Further, osmolality of lithium-heparin plasma was stable when stored at room temperature for 2 (Westgaard guidelines), 3 (SEQC-ML guidelines), or 4 days (RCPA-QAP guidelines) but only for 1 (Westgaard guidelines) or 2 days (SEQC-ML and RCPA-QAP guidelines).
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Not specified
Platform:
Analyte Technology Platform Small molecule Clinical chemistry/auto analyzer Electrolyte/Metal Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Blood and blood products Plasma
Serum
Whole blood
Biospecimen Aliquots and Components Centrifugation Centrifugation delays investigated
Storage Storage temperature Room temperature
4˚C
Storage Storage duration 1 day
2 days
3 days
4 days
5 days
6 days
7 days
10 days
11 days
12 days
14 days
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Study Purpose
This study investigated the effects of storage temperature and duration on the stability of osmolality in urine using three sets of guidelines. Urine was collected from 50 volunteers into sterile containers. Urine was immediately centrifuged at 1000 rpm for 5 min at 4˚C and aliquoted for storage in the dark at room temperature, 4˚C, and -21˚C. Frozen urine was thawed in a 37˚C water bath. Osmolality was determined using an automatic osmometer.
Summary of Findings:
Based on the Westgaard recommendations, urine osmolality was unaffected by 14 days of storage at room temperature, 4˚C, or -21˚C but urine osmolality was only stable for 5 days in urine stored at room temperature based on the SEQC-ML and RCPA-QAP standards, stable in urine stored at 4˚C for 4 (SEQC-ML) and 5 days (RCPA-QAP), and more than 14 days at -21˚C (both standards).
Biospecimens
Preservative Types
- None (Fresh)
- Frozen
Diagnoses:
- Not specified
Platform:
Analyte Technology Platform Small molecule Clinical chemistry/auto analyzer Electrolyte/Metal Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage duration 1 day
2 days
3 days
4 days
5 days
6 days
7 days
10 days
11 days
12 days
14 days
Biospecimen Preservation Type of fixation/preservation Frozen
None (fresh)
Storage Storage temperature Room temperature
4˚C
-21˚C