Serum and plasma fragments of C-telopeptides of type I collagen (CTX) are stable during storage at low temperatures for 3 years.

Author(s): Qvist P, Munk M, Hoyle N, Christiansen C

Publication: Clin Chim Acta, 2004, Vol. 350, Page 167-73

PubMed ID: 15530474 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 frozen storage temperature and duration on CTX concentration and pH of plasma or serum.

   Summary of Findings:

   Frozen storage of serum or EDTA-plasma for up to 3 years did not result in any significant changes in CTX concentrations. The pH of serum and EDTA-plasma specimens increased from 7.8 to 9.1 after 3 years of storage at -20 degrees C, but decreased to 6.5 in specimens stored at -80 degrees C. Only a slight increase in pH to 8.1 was noted in serum specimens stored at -150 for 3 years. The changes in specimen pH occurred predominantly within the first 10 months of storage.

   Biospecimens

   • Bodily Fluid - Serum
   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Peptide	ELISA
   Small molecule	pH

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage temperature	-20 degrees c -80 degrees C -150 degrees C
   Storage	Storage duration	0 days 2 months 4 months 6 months 8 months 10 months 12 months 18 months 30 months 36 months
   Biospecimen Aliquots and Components	Blood and blood products	Plasma Serum
   Preaquisition	Diagnosis/ patient condition	Postmenopausal

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2. Study Purpose

   The purpose of this study was to determine the effects of storage at 4 degrees C for up to 60 days and 37 degrees C for up to 14 days on CTX concentrations in plasma and serum. After storage at 4 or 37 degrees C, all specimens were stored at -20 degrees C until analysis.

   Summary of Findings:

   Storage of serum at 4 degrees C resulted in a decrease in CTX concentrations to 80% of concentrations found in fresh serum after 14 days and to only 35% of those found in fresh serum after 60 days. EDTA-plasma levels were unaffected by storage at 4 degrees C. At 37 degrees C, serum CTX was rapidly lost, but 90% of EDTA-plasma CTX found in fresh specimens was detectable after 2 days. However, EDTA-plasma CTX concentrations continued to decline slowly with storage. In conclusion, for measurement of CTX, EDTA plasma specimens are preferable and may be stored at 4 degrees for up to 60 days.

   Biospecimens

   • Bodily Fluid - Serum
   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Peptide	ELISA

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Aliquots and Components	Blood and blood products	Plasma Serum
   Storage	Storage duration	0 days 2 days 4 days 7 days 14 days 28 days 60 days
   Storage	Storage temperature	-20 degrees C 4 degrees C 37 degrees C

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