A model for an uncertainty budget for preanalytical variables in clinical chemistry analyses.
Author(s): Rynning M, Wentzel-Larsen T, Bolann BJ
Publication: Clin Chem, 2007, Vol. 53, Page 1343-8
PubMed ID: 17495014 PubMed Review Paper? No
Suggested by: ISBER
Purpose of Paper
The purpose of this paper was to determine the effects of preanalytical variables on clinical chemistry analytes in blood specimens
Conclusion of Paper
The use of plain glass tubes versus SST tubes significantly decreased serum levels of creatinine, but no effect of using glass versus plastic SST tubes was found. Increasing the clotting time from 40-70 minutes to 120-150 minutes significantly decreased glucose and calcium. Storing serum for 48 h at room temperature, prior to freezing at -80 degrees C, significantly increased creatinine and decreased glucose. Significantly lower levels of creatinine and higher levels of glucose were measured by a Modular II instrument when compared to levels measured by a Modular I instrument. Centrifugation speed had no effect on any of the analytes.
Studies
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Study Purpose
The purpose of this study was to determine the effects of collection tube type, clotting time, centrifugation speed (1300 x g versus 2350 x g), storage of serum, and instrument type on serum glucose, calcium, magnesium and creatinine levels.
Summary of Findings:
The use of plain glass tubes versus SST tubes significantly decreased serum levels of creatinine (p=0.003), but no effect of using glass versus plastic SST tubes was found (p>0.07). Increasing the clotting time from 40-70 minutes to 120-150 minutes, significantly decreased glucose (p<0.001) and calcium (p<0.001). Storing serum for 48 h at room temperature, prior to freezing at -80 degrees C, significantly increased creatinine (p<0.001) and decreased glucose (p<0.001) when compared to serum left at room temperature for less than 4 hours before freezing. Significantly lower levels of creatinine (p=0.01) and higher levels of glucose (p<0.007) were measured by a Modular II instrument when compared to levels measured by a Modular I instrument. Centrifugation speed had no effect on any of the analytes.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Not specified
Platform:
Analyte Technology Platform Carbohydrate Clinical chemistry/auto analyzer Small molecule Clinical chemistry/auto analyzer Electrolyte/Metal Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage duration 120-150 min
40-70 min
Storage Time at room temperature < 4 h
48 h
Clinical chemistry/auto analyzer Specific Technology platform Roche Modular I
Roche Modular II
Storage Storage temperature -80 degrees C
Biospecimen Acquisition Type of collection container/solution Vacutainer (Becton Dickinson)
Glass serum separator (SST) (Becton Dickinson)
Plastic serum separator (SSTII) (Becton Dickinson)
Biospecimen Aliquots and Components Centrifugation Multiple speeds compared
Centrifugation delays investigated