scholarly journals Reference Measurement Procedure Development for C-Reactive Protein in Human Serum

2009 ◽  
Vol 81 (20) ◽  
pp. 8610-8616 ◽  
Author(s):  
Eric L. Kilpatrick ◽  
David M. Bunk
Keyword(s):  
Human Serum ◽  
Measurement Procedure ◽  
C Reactive Protein ◽  
Reference Measurement ◽  
Reactive Protein ◽  
Reference Measurement Procedure ◽  
Procedure Development

scholarly journals Measurement of Urea in Human Serum by Isotope Dilution Mass Spectrometry: A Reference Procedure

1999 ◽  
Vol 45 (9) ◽  
pp. 1523-1529 ◽  
Author(s):  
Anja Kessler ◽  
Lothar Siekmann
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Human Serum ◽  
Isotope Dilution ◽  
Accurate Determination ◽  
Measurement Procedure ◽  
Gas Chromatography Mass Spectrometry ◽  
Reference Measurement ◽  
Chromatography Mass Spectrometry ◽  
Reference Measurement Procedure

Abstract Background: A reference measurement procedure is needed to demonstrate the traceability of results of urea measurements in human serum. We developed a measurement procedure using the principle of isotope dilution gas chromatography/mass spectrometry. Methods: [13C,15N2]Urea as internal standard was added to a serum sample and equilibrated with endogenous nonlabeled urea. For the preparation of calibrators, the same amount of labeled urea was mixed with known amounts of nonlabeled urea. The serum samples were treated with ethanol to remove proteins by precipitation. The labeled and nonlabeled urea of the samples was converted into a trimethylsilyl derivative of 2-hydroxypyrimidine. The gas chromatography/mass spectrometry system was adjusted to monitor m/z 153 and 168 for the nonlabeled urea derivative and m/z 156 and 171 for the isotopically labeled analogs. The results of the determination were calculated from peak ratios by a hyperbolic calculation function based on the theory of isotope dilution analysis. Results: The procedure was applied to control samples and patient samples and evaluated with respect to its trueness and precision. The standard uncertainty of the results was 0.47–1.72%. Conclusions:This reference measurement procedure allows values to be assigned to controls and calibrators that are traceable to the primary urea reference material of NIST and, therefore, to the Système International unit “mole” with a low degree of uncertainty. This procedure provides a tool for the highly accurate determination of urea in control materials as well as in patient sera.

scholarly journals Interactions of C-reactive protein with the complement system. III. Complement-dependent passive hemolysis initiated by CRP.

1975 ◽  
Vol 142 (5) ◽  
pp. 1065-1077 ◽  
Author(s):  
A.P. Osmand ◽  
R.F. Mortensen ◽  
Joan Siegel ◽  
H. Gewurz
Keyword(s):  
Guinea Pig ◽  
Human Serum ◽  
Complete System ◽  
Gel Filtration ◽  
C Reactive Protein ◽  
Inflammatory Reactions ◽  
Reactive Protein ◽  
Rabbit Igg ◽  
The Complement System ◽  
Pig Serum

Interactions of CRP with various substrates in the presence of human serum have been shown to result in efficient activation of C components C1-C5. We now report the ability of CRP to initiate C-dependent hemolysis. For this purpose CRP was isolated by affinity chromatography using pneumococcal CPS and gel filtration; its purity was established by several criteria. Erythrocytes were coated with CPS (E-CPS) and passively sensitized with CRP. C-dependent lysis of these cells was observed upon the addition of suitably absorbed human serum, and the efficiency of hemolysis compared favorably with that initiated by rabbit IgG anti-CPS antibody. CRP also sensitized E-CPS for lysis by guinea pig C; partial lysis was seen when C4-deficient guinea pig serum was used, suggesting that CRP also shares with antibody the ability of CRP to fully activate the C system and provide further evidence for a role for CRP similar to that of antibody in the initiation and modulation of inflammatory reactions via the complete system.

scholarly journals Phosphoethanolamine-complexed C-reactive protein: A pharmacological-like macromolecule that binds to native low-density lipoprotein in human serum

2008 ◽  
Vol 394 (1-2) ◽  
pp. 94-98 ◽  
Author(s):  
Sanjay K. Singh ◽  
Madathilparambil V. Suresh ◽  
Deborah C. Prayther ◽  
Jonathan P. Moorman ◽  
Antonio E. Rusiñol ◽  
...  
Keyword(s):  
Human Serum ◽  
Low Density Lipoprotein ◽  
Protein A ◽  
Density Lipoprotein ◽  
Low Density ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Native Low Density Lipoprotein

scholarly journals Proposed Serum Cholesterol Reference Measurement Procedure by Gas Chromatography–Isotope Dilution Mass Spectrometry

2011 ◽  
Vol 57 (4) ◽  
pp. 614-622 ◽  
Author(s):  
Selvin H Edwards ◽  
Mary M Kimberly ◽  
Susan D Pyatt ◽  
Shelton L Stribling ◽  
Kara D Dobbin ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Serum Cholesterol ◽  
Isotope Dilution ◽  
Isotope Dilution Mass Spectrometry ◽  
Measurement Procedure ◽  
Standard Reference Materials ◽  
Reference Measurement ◽  
Reference Measurement Procedure ◽  
The Mean

BACKGROUND Our purpose was to establish a mass spectrometry reference measurement procedure (RMP) for cholesterol to use in the CDC's standardization programs. We explored a gas chromatography–isotope dilution mass spectrometry (GC-IDMS) procedure using a multilevel standard calibration curve to quantify samples with varying cholesterol concentrations. METHODS We calibrated the mass spectrometry instrument by isotope dilution with a pure primary standard reference material and an isotopically enriched cholesterol analog as the internal standard (IS). We diluted the serum samples with Tris-HCl buffer (pH 7.4, 0.05 mol/L, 0.25% Triton X-100) before analysis. We used 17 serum pools, 10 native samples, and 2 standard reference materials (SRMs). We compared the GC-IDMS measurements with the CDC's modified Abell–Levy–Brodie–Kendall (AK) RMP measurements and assessed method accuracy by analyzing 2 SRMs. We evaluated the procedure for lack of interference by analyzing serum spiked with a mixture of 7 sterols. RESULTS The mean percent bias between the AK and the GC-IDMS RMP was 1.6% for all samples examined. The mean percent bias from NIST's RMP was 0.5% for the SRMs. The total %CVs for SRM 1951b levels I and II were 0.61 and 0.73%, respectively. We found that none of the sterols investigated interfered with the cholesterol measurement. CONCLUSIONS The low imprecision, linear response, lack of interferences, and acceptable bias vs the NIST primary RMP qualifies this procedure as an RMP for determining serum cholesterol. The CDC will adopt and implement this GC-IDMS procedure for cholesterol standardization.

A Diagnostic Platform for Rapid, Simultaneous Quantification of Procalcitonin and C-Reactive Protein in Human Serum

2021 ◽  
Author(s):  
Xiangkun Cao ◽  
Ongagna Y. Serge Yvon ◽  
Ruisheng Wang ◽  
Yue Ren ◽  
Balaji Srinivasan ◽  
...  
Keyword(s):  
Human Serum ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Simultaneous Quantification

Verification of Low-Density Lipoprotein Cholesterol Levels Measured by Anion-Exchange High-Performance Liquid Chromatography in Comparison with Beta Quantification Reference Measurement Procedure

2020 ◽  
Author(s):  
Daisuke Manita ◽  
Hiroshi Yoshida ◽  
Isao Koyama ◽  
Masakazu Nakamura ◽  
Yuji Hirowatari
Keyword(s):  
Anion Exchange ◽  
Clinical Laboratory ◽  
Measurement Procedure ◽  
Calculation Methods ◽  
Serum Samples ◽  
Cvd Risk ◽  
Blood Samples ◽  
Reference Measurement ◽  
Reference Measurement Procedure ◽  
Homogeneous Assays

Abstract Background A new lipoprotein testing method based on anion-exchange HPLC (AEX-HPLC) was recently established. We verified the accuracy of LDL-C levels, a primary therapeutic target for the prevention of cardiovascular disease (CVD), measured by AEX-HPLC comparing with LDL-C levels measured by beta quantification-reference measurement procedure (BQ-RMP), homogenous assays, and calculation methods. Methods We compared LDL-C levels measured by AEX-HPLC (adLDL-Ch: LDL-Ch and IDL-Ch) and BQ-RMP using blood samples from 52 volunteers. AdLDL-Ch levels were also compared with those measurements by homogeneous assays and calculation methods (Friedewald equation, Martin equation, and Sampson equation) using blood samples from 411 participants with dyslipidemia and/or type 2 diabetes. Results The precision and accuracy of adLDL-Ch were verified by BQ-RMP. The mean percentage bias [bias (%)] for LDL-C was 1.2%, and the correlation was y = 0.990x + 3.361 (r = 0.990). These results met the acceptable range of accuracy prescribed by the National Cholesterol Education Program. Additionally, adLDL-Ch levels were correlated with LDL-C levels measured by the 2 homogeneous assays (r > 0.967) and the calculation methods (r > 0.939), in serum samples from patients with hypertriglyceridemia. Conclusions AEX-HPLC is a reliable method for measuring LDL-C levels for CVD risk in daily clinical laboratory analyses.

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