Reevaluation of C-Reactive Protein in Cancer Sera by Radioimmunoassay and Radial Immunodiffusion

Abstract I describe a rapid, simple immunoturbidimetric method for determining C-reactive protein in serum. With the Instrumentation Laboratory Multistat III microcentrifugal analyzer, quantitative results are obtained automatically after a few minutes of reaction time. Within-run and between-run coefficients of variation ranged from 2.5 to 12.7% at C-reactive protein concentrations of 55 to 69 and 14 to 25 mg/L, respectively, normal values being less than 10 mg/L. Comparison with the commercially available radial immunodiffusion method (y) yields the regression equation y = 1.011x - 2.112 (r = 0.979, n = 100).

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Four immunochemical methods for measuring C-reactive protein in plasma compared.

Clinical Chemistry ◽

10.1093/clinchem/35.3.461 ◽

1989 ◽

Vol 35 (3) ◽

pp. 461-463 ◽

Cited By ~ 7

Author(s):

S Grützmeier ◽

H von Schenck

Keyword(s):

Enzymatic Degradation ◽

Close Agreement ◽

Radial Immunodiffusion ◽

C Reactive Protein ◽

Reactive Protein ◽

Laser Nephelometry ◽

Immunochemical Methods ◽

Good Agreement

Abstract Four immunochemical methods for measuring C-reactive protein (CRP) in plasma were compared: radial immunodiffusion (RID), electroimmunoassay (EIA), immunoturbidimetry (IT), and laser nephelometry (LN). Close agreement was found between RID and EIA (EIA = 0.96 RID + 7.7 mg/L, r = 0.977, n = 100), IT and EIA (EIA = 1.11 IT - 15.8 mg/L, r = 0.951, n = 100), IT and RID (RID = 1.10 IT - 11.5 mg/L r = 0.959, n = 94). In initial studies in 1983, LN showed good agreement with RID (LN = 0.98 RID + 11.9 mg/L, r = 0.973, n = 60). Since then, normal CRP values measured by LN have tended to increase and, at the time of the present study (1986), LN agreed poorly with other methods. The reason for this change is obscure. Having excluded the possibility of enzymatic degradation of CRP, we conclude that instrumentation problems are involved, and therefore we no longer use this method.

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Enhanced-latex-agglutination assay for C-reactive protein in serum, with use of a centrifugal analyzer.

Clinical Chemistry ◽

10.1093/clinchem/33.5.685 ◽

1987 ◽

Vol 33 (5) ◽

pp. 685-689 ◽

Cited By ~ 7

Author(s):

J Winkles ◽

J Lunec ◽

I Deverill

Keyword(s):

Rheumatoid Factor ◽

Latex Agglutination ◽

Radial Immunodiffusion ◽

C Reactive Protein ◽

Agglutination Assay ◽

Reactive Protein ◽

Wide Range ◽

Latex Agglutination Assay

Abstract This is an improved assay of C-reactive protein in serum, for use with the Baker "Encore" centrifugal analyzer. Features of this assay include: 250-specimen throughput per hour, within-batch CV 2.2%, between-batch CV 2.7%, no antigen-excess problems up to 1000 mg/L, negligible interference from rheumatoid factor, and good correlation (r = 0.99) with radial immunodiffusion. The method is inexpensive and automated, involving no predilution steps. It can be adapted for use in a wide range of systems and can be used for single urgent estimations.

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Turbidimetric immunoassay of serum C-reactive protein.

Clinical Chemistry ◽

10.1093/clinchem/28.10.2121 ◽

1982 ◽

Vol 28 (10) ◽

pp. 2121-2124 ◽

Cited By ~ 47

Author(s):

S Otsuji ◽

H Shibata ◽

M Umeda

Keyword(s):

Radial Immunodiffusion ◽

Tween 20 ◽

C Reactive Protein ◽

Standard Curve ◽

Reactive Protein ◽

Analytical Recovery ◽

Polyethylene Glycol 6000 ◽

Sample Dilution ◽

Immunoprecipitation Reaction ◽

Turbidimetric Immunoassay

Abstract This rapid, reliable equilibrium turbidimetric immunoassay for serum C-reactive protein involves a potent monospecific antibody. Polyethylene glycol-6000 to accelerate and enhance the immunoprecipitation reaction, and Tween-20 surfactant to lower and stabilize the sample blank values. Grossly lipemic, icteric, or hemolyzed sera can be assayed. Values up to about 220 mg/L, for which the standard curve is linear, can be measured without sample dilution. Results by the proposed method and by radial immunodiffusion (r 0.989) or laser nephelometry (r = 0.957) correlated well. Analytical recovery averaged 101.3%. Within-, between-, and day-to-day CVs ranged from 0.9% to 3.5%, 0.8% to 5.5%, and 1.9% to 4.8%, respectively. The method is demonstrably superior to radial immunodiffusion or nephelometry. Any spectrophotometer that can measure turbidimetrically at 340 nm can be used.

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Immunoturbidimetry of Serum C-Reactive Protein in Low Concentration of Polyethylene Glycol

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456328502200309 ◽

1985 ◽

Vol 22 (3) ◽

pp. 269-272 ◽

Cited By ~ 8

Author(s):

I Byrjalsen ◽

S H Ingwersen

Keyword(s):

Polyethylene Glycol ◽

Radial Immunodiffusion ◽

C Reactive Protein ◽

Low Concentration ◽

Reactive Protein ◽

Polyethylene Glycol 6000

A simple, rapid immunoturbidimetric assay for determination of serum C-reactive protein is presented. In order to obtain constant sample blank values within a few minutes we found it necessary to use a low concentration (10 g/L) of polyethylene glycol 6000 in contrast to the commonly used 40 g/L PEG solution. The sensitivity of the assay presented is 7 mg/L; within-run and between-run CVs ranged respectively from 1·4% to 2·4% and from 2·1% to 5·5%. Results obtained with the proposed method correlate well with radial immunodiffusion.

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