Microparticle‐enhanced nephelometric immunoassay for human C‐reactive protein

Abstract

Polyfunctional hydrophilic microspheres of 125-nm diameter can be produced by copolymerization of acrylic monomers. Purified c-reactive protein (CRP) was covalently bound to these new micropheres, and the conjugate obtained was used as reagent in a microparticle-enhanced nephelometric immunoassay for human CRP. This assay was based on the measure, with a specially designed nephelometer, of the light scattered by aggregates formed during the immunoagglutination of the conjugate with anti-CRP antiserum. Sensitive inhibition of this agglutination by free CRP (6 ng/ml) allowed CRP quantitation in highly diluted serum samples (1/500-1/2,000), excluding any interference or sample pretreatment. The CRP assay was easy to perform (no washing or phase separation), reliable (coefficients of variation ranged from 1.3% to 9.3% for within-run and between-run determinations), and accurate (mean percentage of recovery: 104%; correlation coefficients with accepted analytical methods greater than or equal to 0.97) over a large range of concentrations. The inhibition mode excluded errors in the antigen excess zone and provided total security at high concentrations.

Increased levels of C-reactive protein and fibrinogen influence the risk of vascular events in patients with NIDDM

“…High-sensitivity C-reactive protein (hs-CRP) was determined by the nephelometric method (Beckman Instrument APS); the sensitivity of this method has previously been validated; we considered high values N0.30 mg/dL [10].…”

Markers of Inflammation and Infection Influence the Outcome of Patients With Baseline Asymptomatic Carotid Lesions

“…6 High-sensitive CRP was determined by the nephelometric method (Beckman Instrument APS), 7 and high levels are considered those Ͼ3 mg/L. 8 IgG-specific antibodies for CMP, CMV, and HP were measured by ELISA.…”

Circulating C reactive protein in osteoarthritis: a systematic review and meta-analysis

“…An immunoassay was introduced in 1992 by Montagne et al 8 to perform high sensitive CRP (hs-CRP) measurement. In 1997, a study by Loose et al showed that OA patients had higher serum hs-CRP levels than age-matched controls 9.…”