C-reactive protein: the difference between quantitation is serum and EDTA plasma.
Scand J Clin Lab Invest
; 56(2): 123-7, 1996 Apr.
Article
in En
| MEDLINE
| ID: mdl-8743104
ABSTRACT
We report the differences between using either EDTA plasma or serum in a turbidimetric assay for quantitation of C-reactive protein (CRP). A systematic discrepancy was found for these two sample materials. This was most pronounced in the low concentration range (below 20 mg1(-1)) at which lower values were found in serum than in EDTA plasma. Conversely, in the high concentration range, serum showed slightly higher values. Addition of K3-EDTA to the reaction buffer improved the kinetics for sera with low concentrations of CRP, thus increasing the sensitivity of the assay. We found an overall constant discrepancy of approximately 8% lower values in plasma than in serum (equally for low and high levels of CRP) after the addition of K3-EDTA. The most probable explanation for this effect seems to be the differing water content of serum and EDTA plasma. We discuss the role and function of EDTA in the CRP assay and suggest some hypothetical mechanisms.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Blood Chemical Analysis
/
C-Reactive Protein
/
Edetic Acid
Limits:
Humans
Language:
En
Journal:
Scand J Clin Lab Invest
Year:
1996
Document type:
Article
Affiliation country:
Sweden