Laboratory Diagnosis of Thrombosis
Hau C. Kwaan, Meyer M. Samama in Clinical Thrombosis, 2019
Measurement of plasminogen can be carried out by both immunologic and functional techniques. The functional assays are usually based on conversion of plasminogen to plasmin with subsequent measurement of total activity by clotting assays or with synthetic substrates. Radial immunodiffusion and Laurell rocket electrophoresis are the most common methods utilized to measure the antigenic component. A variety of commercial products are available for both techniques, and some of the functional assays have been automated. Both functional and immunologic methods may be necessary for adequate classification of functional plasmin deficiency. More recently, functional and antigenic measurement of tissue plasminogen activator has been described, though these procedures are not yet widely available.28
Hypersensitivity
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2020
Serum concentrations of complement components can be measured by the radial immunodiffusion test. Specific antisera against individual components are incorporated into agar, and the patient's serum is placed in wells in the agar. Raised concentrations of components of complement are frequently found in acute inflammation. A reduction in concentration of complement can be due to: Primary genetically determined immunodeficiency disorders.Secondary deficiencies caused by complement consuming antibody–antigen interactions or associated with liver or renal disease. Complement activation in allergic reactions is usually associated with decreases in C3 or C4 concentrations in serum or increases in concentrations of products of complement activation (e.g. C3a, C4a and C5a).
Immunological Approaches
Adorjan Aszalos in Modern Analysis of Antibiotics, 2020
The diffusion procedure, the basis of the classic microbiological procedures that have been used to measure antibiotics, can be used to assay antibiotics using the antigen-antibody reaction. Radial immunodiffusion is quite similar to the agar well diffusion procedure. Agar containing antibody is poured onto a suitable glass surface, and wells are cut. The solution containing the antigen (the antibiotic) is pipetted into the well. After a period of diffusion, at a constant temperature, a ring of precipitin forms. The diameter of the ring is proportional to the concentration of the antigen. As in the classic microbial diffusion assay, a standard curve is prepared and the concentration of the unknown is determined from the curve [8].
Prognostic value of cryoglobulins, protein electrophoresis, and serum immunoglobulins for lymphoma development in patients with Sjögren’s syndrome. A retrospective cohort study
Published in Acta Clinica Belgica, 2018
Jesse Kimman, Xavier Bossuyt, Daniel Blockmans
For the detection and quantification of cryoglobulins, blood samples were taken by venipuncture in pre-heated (to 37 °C) 10 mL serum tubes. Until the serum was separated, all tubes were maintained at 37 °C. The serum samples were transported at ambient temperature, and reheated to 37 °C before further processing [29]. Aliquots of serum were allowed to precipitate at 4 °C for 7 days. These samples were washed three times with phosphate-buffered saline (PBS) at 4 °C and dissolved in PBS at 37 °C. This material was subjected to electrophoresis and identification of monoclonal proteins. Individual immunoglobulin levels (IgA, IgG, and IgM) were quantified with NOR-Partigen® reagents on radial immunodiffusion until 2004, Turbiquant® reagents on Turbitimer (Dade-Behring) until 2012, and thereafter on Immage (Beckman Coulter) [29].
Quantification methods for viruses and virus-like particles applied in biopharmaceutical production processes
Published in Expert Review of Vaccines, 2022
Keven Lothert, Friederike Eilts, Michael W. Wolff
Alternative approaches for antigen detection and quantification are the single radial immunodiffusion assay (SRID) [61] and the hemagglutination assay [62,63], both described already in the 1950s and 1960s, and still being routinely applied for the indirect quantification of viruses. To date, the SRID is used for the regulatory release of human influenza vaccines [64–66]. In both assays, the surface protein hemagglutinin, and thereby the amount of virus particles, can be estimated for viruses carrying that specific antigen, such as the influenza or the measles viruses. Thus, many reports on these two assays focus on influenza vaccine production and processing [67–72]. However, these assays are also used for a series of other viruses. Recently, Cheng et al. described the quantification of the porcine circovirus type 2 by a hemagglutination assay for virus concentrations of down to 104 TCID50 per ml [73].
Revisiting the complement system in systemic lupus erythematosus
Published in Expert Review of Clinical Immunology, 2020
Madhubala Sharma, Pandiarajan Vignesh, Karalanglin Tiewsoh, Amit Rawat
Estimation of C3 and C4 levels is one of the commonly performed laboratory tests. A plasma or serum sample is used that has to be separated and stored at −80°C within few hours of sample collection to avoid in-vitro complement activation. Multiple techniques involving enzyme-linked immunosorbent assays (ELISA), nephelometry, radial-immunodiffusion, and western blot, etc. are few of the methods intended for assessment of complement components like C1q, C1 r, C1 s, C2, C3, C4, and their derived products. Age-related normograms need to be used for correct interpretation of results, especially in children. For all these immunoassays, choice of specific antibody is crucial. Most antibodies used are polyclonal and measure different protein variants [99].
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