Biomaterial Database

Enzyme-linked immunosorbent assay that uses labeled antigen for detection of immunoglobulin M and A antibodies in toxoplasmosis: comparison with indirect immunofluorescence and double-sandwich enzyme-linked immunosorbent assay. 1983

A M van Loon, and J T van der Logt, and F W Heessen, and J van der Veen

A direct enzyme-linked immunosorbent assay (ELISA) is described that uses horseradish peroxidase-labeled antigen for detection of immunoglobulin M (IgM) and IgA antibodies to toxoplasma. In this assay, polystyrene microtiter plates were sensitized with anti-human IgM or IgA antibody to separate IgM or IgA from other classes of antibody. The presence of IgM or IgA antibodies to toxoplasma (Tox-IgM, Tox-IgA) was then detected by sequential addition of soluble horseradish peroxidase-labeled toxoplasma antigen and substrate. As judged by examining sucrose gradient-fractionated sera, the assay was specific for IgM or IgA classes of antibody. In contrast to the indirect immunofluorescence for IgM antibodies to toxoplasma, no inhibition of IgM reactivity by specific IgG antibodies could be detected. Furthermore, rheumatoid factor did not cause false-positive results. Of 80 single sera with high antibody titer to toxoplasma in indirect immunofluorescence and complement fixation, 40 were positive in the direct ELISA for Tox-IgM, 36 were positive in the double-sandwich ELISA, and only 21 were positive in the indirect immunofluorescence for Tox-IgM when whole serum was used. In the indirect immunofluorescence, another 13 sera became positive after sucrose gradient fractionation. The direct ELISA for IgA antibodies to toxoplasma was positive in 43 sera, of which 39 were positive in the direct ELISA for Tox-IgM. High levels of IgM antibodies were found within 3 months after the onset of symptoms, slowly decreasing thereafter. Tox-IgM may persist for more than 1 year after infection.

UI	MeSH Term	Description	Entries
D007070	Immunoglobulin A	Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.	IgA,IgA Antibody,IgA1,IgA2,Antibody, IgA
D007075	Immunoglobulin M	A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally was called a macroglobulin.	Gamma Globulin, 19S,IgM,IgM Antibody,IgM1,IgM2,19S Gamma Globulin,Antibody, IgM
D004306	Dose-Response Relationship, Immunologic	A specific immune response elicited by a specific dose of an immunologically active substance or cell in an organism, tissue, or cell.	Immunologic Dose-Response Relationship,Relationship, Immunologic Dose-Response,Dose Response Relationship, Immunologic,Dose-Response Relationships, Immunologic,Immunologic Dose Response Relationship,Immunologic Dose-Response Relationships,Relationship, Immunologic Dose Response,Relationships, Immunologic Dose-Response
D004797	Enzyme-Linked Immunosorbent Assay	An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.	ELISA,Assay, Enzyme-Linked Immunosorbent,Assays, Enzyme-Linked Immunosorbent,Enzyme Linked Immunosorbent Assay,Enzyme-Linked Immunosorbent Assays,Immunosorbent Assay, Enzyme-Linked,Immunosorbent Assays, Enzyme-Linked
D005455	Fluorescent Antibody Technique	Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.	Antinuclear Antibody Test, Fluorescent,Coon's Technique,Fluorescent Antinuclear Antibody Test,Fluorescent Protein Tracing,Immunofluorescence Technique,Coon's Technic,Fluorescent Antibody Technic,Immunofluorescence,Immunofluorescence Technic,Antibody Technic, Fluorescent,Antibody Technics, Fluorescent,Antibody Technique, Fluorescent,Antibody Techniques, Fluorescent,Coon Technic,Coon Technique,Coons Technic,Coons Technique,Fluorescent Antibody Technics,Fluorescent Antibody Techniques,Fluorescent Protein Tracings,Immunofluorescence Technics,Immunofluorescence Techniques,Protein Tracing, Fluorescent,Protein Tracings, Fluorescent,Technic, Coon's,Technic, Fluorescent Antibody,Technic, Immunofluorescence,Technics, Fluorescent Antibody,Technics, Immunofluorescence,Technique, Coon's,Technique, Fluorescent Antibody,Technique, Immunofluorescence,Techniques, Fluorescent Antibody,Techniques, Immunofluorescence,Tracing, Fluorescent Protein,Tracings, Fluorescent Protein
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000918	Antibody Specificity	The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.	Antibody Specificities,Specificities, Antibody,Specificity, Antibody
D000941	Antigens	Substances that are recognized by the immune system and induce an immune reaction.	Antigen
D012217	Rheumatoid Factor	Autoantibodies found in adult RHEUMATOID ARTHRITIS patients that are directed against GAMMA-CHAIN IMMUNOGLOBULINS.	Factor, Rheumatoid
D014122	Toxoplasma	A genus of protozoa parasitic to birds and mammals. T. gondii is one of the most common infectious pathogenic animal parasites of man.	Toxoplasma gondii,Toxoplasma gondius,Toxoplasmas,gondius, Toxoplasma