E xamination of cerebrospinal fluid (CSF) total protein is used chiefly to detect increased permeabili ty of the blood-brain barrier to plasma proteins or increased intrathecal secretion of immunoglobulins (1). A rapid and quite precise method is required. The biuret method is considered as a potential reference method for total protein determination in biological fluids (2-4). It has been modi...

Objective: This study aimed to evaluate the diagnostic usefulness of second and third generation anticyclic citrullinated peptide (anti-CCP2 and anti-CCP3) assays in Chinese patients with rheumatoid arthritis (RA), and to identify the potential advantages of anti-CCP3 diagnosis in rheumatoid factor (RF) negative RA patients. Methods: Serum samples were obtained from 148 RA patients and 120 cont...

In the present study we demonstrate that a bulk inverse micellar cubic phase of Fd3m structure can be obtained by adding a hydrophobic component, such as the food-grade limonene, to the binary system monolinolein/water in a well-defined composition. The Fd3m structure studied in this work had a very slow kinetics of formation, as a consequence of partitioning of water into two types of micelle ...

BACKGROUND C-reactive protein (CRP) is able to bind phospholipids (mainly phosphocholine) in the presence of calcium ions. We investigated the use of this property for developing an affordable turbidimetrical CRP assay based on diluted soy oil. METHODS Serum (or heparinized plasma) was mixed with Intralipid 20% in Tris-calcium buffer (pH 7.5). After 30 min of incubation at 37 degrees C, the C...

We studied a serum component ("pseudolipase") that interferes with both turbidimetric and nephelometric lipase measurements. Pseudolipase activity in serum was found in the presence of rheumatoid factor and in other disorders of active immune processes. The incidence of this interferent in sera seems to be greater than reported previously. We describe a method for eliminating its effect without...

A sensitive immunoassay based on latex particle agglutination for the measurement of circulating IgE-containing complexes is described. In this method, the anti-IgE-coated particles are incubated with diluted serum and the resulting agglutination is quantified by turbidimetry or particle counting. In the latter version, the assay is fully automated in a continuous flow system. IgE-containing co...

Loop-mediated isothermal amplification (LAMP) is a nucleic acid amplification method that allows the synthesis of large amounts of DNA in a short period of time with high specificity. As the LAMP reaction progresses, the reaction by-product pyrophosphate ions bind to magnesium ions and form a white precipitate of magnesium pyrophosphate. We designed an apparatus capable of measuring the turbidi...

We describe the simple, rapid turbidimetry of IgM rheumatoid factor in human serum by use of the Cobas-Bio centrifugal analyzer. Heat-aggregated human IgG is used as the antigen. The immunoturbidimetric reaction is monitored at 340 nm for 300 s, and the changes in absorbance after the antigen is added are used to prepare the standard curve. Test results are calculated from the stored curve and ...

Applications of the three principal light scattering techniques of turbidimetry, differential light scattering, and quasi-elastic light scattering to systems of microorganisms are reviewed. The relation between the three techniques is demonstrated and it is shown how these techniques can yield basic structural, optical, and even hydrodynamic properties for a wide range of microorganisms, with p...