Effect of anticoagulants and storage temperatures on stability of plasma and serum hormones.

Author(s): Evans MJ, Livesey JH, Ellis MJ, Yandle TG

Publication: Clin Biochem, 2001, Vol. 34, Page 107-12

PubMed ID: 11311219 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of anticoagulant type, storage duration, and storage temperature on a group of 22 hormones in plasma and serum. After experimental storage, all specimens were frozen at -20 degrees C until analysis. Actual measurements were only taken after 24 or 120 h of storage of specimens at 4 or 30 degrees C, but the time elapsing before the median immunoreactivity changed by 10% or more was interpolated (duration of stability).

   Summary of Findings:

   When specimens were stored at -20 degrees C until analysis (no initial storage at 4 or 30 degrees C), 6 of 22 analytes had significantly different levels between serum and EDTA plasma, 4 of 20 analytes had significantly different levels between fluorinated plasma and EDTA plasma, and 3 of 22 had significantly different levels between hepariniated plasma and EDTA plasma. In general, hormone analytes were far less stable when stored at 30 degrees C before being frozen than they were when stored at 4 degrees C. Only 5 of 19 analytes showed anticoagulant-specific durations of stability at 4 degrees C that were observed before the 120 h time point . The authors conclude that fluoride and EDTA served as better anticoagulants for hormone analysis in specimens requiring storage and transport at 4 degrees C for 120 h than heparin or the use of serum. ACTH was notably the least stable analyte at 4 degrees C. On the other hand, only alpha-subunit total, C-peptide, and follicle stimulating hormone (FSH) were stable for >120 h at 30 degrees C for all anticoagulants and serum. While stability was low across the board when specimens were stored at 30 degrees C, in general, analytes were slightly more stable in EDTA plasma than when the other anticoagulants or serum were used, but analyte-specific exceptions were observed.

   Biospecimens

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

   Preservative Types

   • Frozen

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Peptide	Immunoradiometric assay
   Glycoprotein	Radioimmunoassay
   Peptide	Radioimmunoassay
   Steroid	Radioimmunoassay
   Protein	Radioimmunoassay
   Glycoprotein	Immunoassay

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Anticoagulant	EDTA Lithium heparin Sodium fluoride/potassium oxalate
   Storage	Storage temperature	-20 degrees C 4 degrees C 30 degrees C
   Storage	Storage duration	0 h 24 h 120 h
   Biospecimen Aliquots and Components	Blood and blood products	Plasma Serum

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2. Study Purpose

   The purpose of this study was to determine the effects of anticoagulant type and room temperature storage, before or after centrifugation, on measurement of BNP and NT-BNP in plasma. All specimens were frozen at -20 degrees C until analysis. The time elapsing before the median immunoreactivity changed by 10% or more was interpolated from the data points to determine the duration of stability.

   Summary of Findings:

   BNP was stable for 20 hours when EDTA whole blood was stored at room temperature and for 18 hours when EDTA plasma was stored at room temperature. BNP was slightly less stable when heparinated plasma was stored at room temperature, showing a greater than 10% change after just 10 hours, but the stability in heparinated whole blood was not reported. NT-BNP was less stable than BNP across the board, with room temperature durations of stability in EDTA whole blood, heparinated whole blood, EDTA plasma, and heparinated plasma of 5, 4, 7, and 8 hours, respectively.

   Biospecimens

   • Bodily Fluid - Blood
   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen

   Diagnoses:

   • Cardiovascular Disease

   Platform:

   Analyte	Technology Platform
   Peptide	Radioimmunoassay

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Anticoagulant	EDTA Lithium heparin
   Storage	Time at room temperature	0 h 6 h 24 h 48 h 72 h
   Biospecimen Aliquots and Components	Blood and blood products	Plasma Whole blood
   Biospecimen Aliquots and Components	Centrifugation	Centrifugation delays investigated

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