| double antibody precipitation | A method of separating antibody-bound antigen (e.g., insulin) from free antigen by precipitating the former with antibody specific for immunoglobulin. Synonym: double antibody immunoassay, double antibody method. (05 Mar 2000) |
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| double antibody sandwich assay | For antigen; an application of the ELISA method in which material being tested for antigen is added to wells coated with known antibody; the presence of antigen fixed to the antibody coat can be determined either directly, by adding human antibody linked to the enzyme of the indicator system, or indirectly, by first adding unlabelled known antibody, the attachment of which to the antigen can be demonstrated by addition of immunoglobulin-specific antibody linked to the enzyme. (05 Mar 2000) |
| idiotype antibody | <immunology> An antibody directed against the antigen specific part of the sequence of an antibody or T-cell receptor and thus recognise the binding sites of other antibodies. In principle an anti-idiotype antibody should inhibit a specific immune response and they are important to the regulation of the immune system. (13 Nov 1997) |
| IgM antibody capture ELISA | Developed to impart significant improvement in assay specificity to indirect ELISA procedures for IgM isotype antibodies. Solid-phase support (usually microtitre plate wells) are coated with anti-human IgM antibodies capable of binding all IgM isotype antibodies present in the specimen. Reagent antigen is then added, followed by enzyme-labelled antigen-specific antibodies. If IgM antibodies specific for the antigen in question are present, the "sandwich" complex will result in enzymatic colour-change proportional to the concentration of IgM-specific antibody present. This technique appears to be the method of choice in many highly specific and more sensitive assays for IgM infectious disease antibodies. Acronym: MAC ELISA (05 Mar 2000) |
| immobilizing antibody | Antibody, evoked during syphilitic infections, possessing specific affinity for Treponema pallidum, and which in the presence of complement immobilises the organism. Synonym: immobilizing antibody, treponemal antibody. (05 Mar 2000) |
| incomplete antibody | An "incomplete" form of antibody that may coat antigen, but which according to the "lattice theory" does not have a second receptor for attachment to another molecule of antigen; in the case of Rh+ erythrocytes, such an anti-Rh antibody may coat the cells but not cause them to agglutinate in saline; however, agglutination does occur when such coated cells are suspended in serum or other protein media, such as albumin, therefore called serum agglutinin. Synonym: incomplete antibody, inhibiting antibody. (05 Mar 2000) |
| indirect fluorescent antibody | The detection of antibodies to specific antigenic material in the substrate using fluorescent microscopy. Using fluorescent conjugated antibodies which are specific for a particular isotype of antibody, it is possible to distinguish IgG, IgA and IgM isotypes of specific antibodies using indirect fluorescent antibody. This sensitive technique is highly specific in well-trained hands and recent developments in the establishment of internationally recognised standard materials have led to accurate quantitation of antibody concentrations through endpoint titration (the highest serial dilution of specimen at which specific fluorescence remains) and through measuring visual intensity of fluorescence compared to known reference standard material. (05 Mar 2000) |
| inhibiting antibody | An "incomplete" form of antibody that may coat antigen, but which according to the "lattice theory" does not have a second receptor for attachment to another molecule of antigen; in the case of Rh+ erythrocytes, such an anti-Rh antibody may coat the cells but not cause them to agglutinate in saline; however, agglutination does occur when such coated cells are suspended in serum or other protein media, such as albumin, therefore called serum agglutinin. Synonym: incomplete antibody, inhibiting antibody. (05 Mar 2000) |
| thyroglobulin antibody | <investigation> A serologic blood test which measures the antithyroglobulin antibodies in the blood. Thyroglobulin is a protein found in thyroid tissue. It is the source of thyroid hormones in the body. The presence of antibodies to this protein can result in decreased thyroid gland function. A negative assay is considered normal. Conditions where the assay may be positive include: lupus, rheumatoid arthritis, Hashimoto's thyroiditis, thyrotoxicosis, hypothyroidism, thyroid cancer, myxoedema, Sjogren's syndrome and autoimmune haemolytic anaemia. (07 Mar 2000) |
| thyroid receptor antibody | A test that measures the amount of an antibody (thyroid stimulating antibody) which is directed against a receptor for TSH on the thyroid gland. This antibody acts like TSH and stimulates the thyroid to produce excessive amounts of thyroid hormone. The presence of this antibody generally indicates Grave's disease (hyperthyroidism). (27 Sep 1997) |
| thyroid stimulating antibody | <endocrinology, immunology> Long acting thyroid stimulator is an autoantibody found in many cases of primary thyrotoxicosis which causes hyperplasia of the thyroid by undetermined mechanisms. Human thyroid stimulating immunoglobulin is a different antibody found in all or nearly all cases of primary thyrotoxicosis and may act by binding to the thyrotropin (TSH) receptor site, causing increased synthesis of thyroglobulin. (18 Nov 1997) |
| toxoplasma antibody titre | A test which measures the presence of antibodies against Toxoplasma in the blood. This test is used to detect congenital or postnatal toxoplasmosis or to screen pregnant women for the presence of Toxoplasma antibodies. The presence of antibodies before pregnancy probably protects the foetus against congenital toxoplasmosis. Antibodies against Toxoplasma that are developed during pregnancy may indicate a congenital infection (increased risk of birth defects and spontaneous abortion). (27 Sep 1997) |
| treponema-immobilizing antibody | Antibody, evoked during syphilitic infections, possessing specific affinity for Treponema pallidum, and which in the presence of complement immobilises the organism. Synonym: immobilizing antibody, treponemal antibody. (05 Mar 2000) |
| treponemal antibody | Antibody, evoked during syphilitic infections, possessing specific affinity for Treponema pallidum, and which in the presence of complement immobilises the organism. Synonym: immobilizing antibody, treponemal antibody. (05 Mar 2000) |
| univalent antibody | An "incomplete" form of antibody that may coat antigen, but which according to the "lattice theory" does not have a second receptor for attachment to another molecule of antigen; in the case of Rh+ erythrocytes, such an anti-Rh antibody may coat the cells but not cause them to agglutinate in saline; however, agglutination does occur when such coated cells are suspended in serum or other protein media, such as albumin, therefore called serum agglutinin. Synonym: incomplete antibody, inhibiting antibody. (05 Mar 2000) |