Inhibition of intrinsic proteolytic activities moderates preanalytical variability and instability of human plasma.
Author(s): Yi J, Kim C, Gelfand CA
Publication: J Proteome Res, 2007, Vol. 6, Page 1768-81
PubMed ID: 17411080 PubMed Review Paper? No
Suggested by: ISBER
Purpose of Paper
The purpose of this paper was to determine the differences in peptide content between serum and plasma specimens and to evaluate the effects of anticoagulant, protease inhibitors, and storage of specimens at room temperature.
Conclusion of Paper
Serum peptide profiles contained more peaks, and higher peaks than plasma, regardless of anticoagulant. Serum peak intensity decreased for the most abundant peaks with time at room temperature, but for lower abundance peaks, intensity increased, and new peaks appeared with time at room temperature. Plasma peptide peaks also changed with time at room temperature, although, not as extensively as serum profiles, and the changes varied with each anticoagulant. The inclusion of protease inhibitor cocktail with specimens collected in EDTA tubes moderated the changes observed in EDTA-plasma with time at room temperature.
Studies
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Study Purpose
The purpose of this study was to determine the differences in peptide content between serum and plasma specimens and to evaluate the effects of anticoagulant, protease inhibitors, and storage of specimens at room temperature.
Summary of Findings:
Serum peptide profiles contained 137 peaks, whereas heparin-plasma, EDTA-plasma, and citrate-plasma profiles included 73, 66, and 57 peaks, respectively. Serum peak intensities were higher than plasma peak intensities, regardless of anticoagulant. However, serum peak intensity decreased for the most abundant peaks with time at room temperature, but for lower abundance peaks, intensity increased, and new peaks appeared with time at room temperature, suggesting proteolysis. Plasma peptide peaks also changed with time at room temperature although, not as extensively as serum profiles did and the changes varied with each anticoagulant. The inclusion of protease inhibitor cocktail with specimens collected in EDTA tubes resulted in lower peak intensities and fewer peaks in the 840 to 1200 mass-to-charge ratio range and higher peak intensities in the 1500 to 1880 mass-to-charge ratio range at time 0. Protease inhibitors also moderated the changes observed in EDTA-plasma with time at room temperature.
Biospecimens
Preservative Types
- Frozen
- None (Fresh)
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Peptide MALDI-TOF MS Protein MALDI-TOF MS Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Blood and blood products Plasma
Serum
Analyte Extraction and Purification Protease inhibitor Cocktail
No protease inhibitor added
Biospecimen Preservation Type of fixation/preservation Frozen
None (fresh)
Storage Storage temperature -80 degrees C
Storage Time at room temperature 0 min
30 min
2 h
4 h
5 h
24 h
48 h
72 h
Biospecimen Acquisition Anticoagulant Potassium EDTA
Lithium heparin
Sodium citrate
None