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Toxoplasma gondii IgG quantitative



1x96 Assays
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Product Name Toxoplasma gondii IgG ELISA.
# of Samples 1 x 96 Assays.
Intended Use The Toxoplasma gondii IgG-ELISA is intended for the qualitative and quantitative determination of IgG class antibodies against Toxoplasma gondii in human serum or plasma (citrate).
Introduction Toxoplasma gondii is a small intracellular parasite, whose live cycle has a sexual and an asexual phase. Sexual development is restricted to the intestinal cells of (probably exclusively) cats; the oocysts formed are excreted and due to their resistant cell walls they may be infectious under advantageous circumstances for at least 1 year. Animals and man are intermediate hosts for the
asexual proliferation of T. gondii: the ingested parasites will proliferate explosively within the host cells lysing them eventually. They disseminate throughout the body via circulation and lymphatic system and though may infect any cell type. In muscle and brain cells cysts are formed which are spheroidal and about 5-100 μm in diameter. Cysts are virtually immortal in the intermediate host.
Toxoplasma gondii is the most common parasite in humans, but its abundance (7-80%) is highly dependent on the geographic area, the socio-economic status and the nutritional customs. Infection only rarely causes toxoplasmosis and usually clinical symptoms are absent, but may produce severe problems in immunosuppressed persons and fetus. Because only a primary infection during pregnancy may be dangerous and even fatal for the unborn (the probability of congenital infection is about 50%), the recent onset of an infection must be excluded. In pregnant women in over 98% of cases, the absence of IgM excludes the possibility of recent infection. In newborns the very presence of anti-toxoplasma IgM is sufficient to confirm a congenital toxoplasmosis, since maternal IgM, unlike IgG, does not cross the placental barrier. But a significant number of infected infants do not develop detectable IgM levels and thus are false negative. In immunosuppressed patients toxoplasmosis causes severe complications mostly by reactivation of an earlier latent infection.
Infection may be identified by
  • PCR
  • Indirect immunofluorescence (IIF)
  • Serology: Detection of antibody production by ELISA.
Principles of the assay The quantitative immunoenzymatic determination of IgG-class antibodies against Toxoplasma gondii is based on the ELISA (Enzyme-linked Immunosorbent Assay) technique.
Microtiter strip wells are precoated with inactivated Toxoplasma gondii antigens to bind corresponding antibodies of the specimen. After washing the wells to remove all unbound sample material horseradish peroxidase (HRP) labelled anti-human IgG conjugate is added. This conjugate binds to the captured Toxoplasma gondii specific antibodies. The immune complex formed by the bound conjugate is visualized by adding Tetramethylbenzidine (TMB) substrate which gives a blue reaction product.
The intensity of this product is proportional to the amount of Toxoplasma gondii specific IgG antibodies in the specimen. Sulphuric acid is added to stop the reaction. This produces a yellow endpoint colour. Absorbance at 450 nm is read using an ELISA microwell plate reader.
Storage and Stability The reagents are stable up to the expiry date stated on the label when stored at 2..8 °C.
Limitations of the Test Bacterial contamination or repeated freeze-thaw cycles of the specimen may affect the absorbance values. Diagnosis of an infectious disease should not be established on the basis of a single test result. A precise diagnosis should take into consideration clinical history, symptomatology as well as serological data.
In immunocompromized patients and newborns serological data only have restricted value.
References A. Balsari et al. ELISA for Toxoplasma antibody detection: a comparision with other serodiagnostic tests. J. Clin. Pathol., 33: 640 (1980)M.H. Beaman, R.E. McCabe, S-Y. Wong, J.S. Remington, Toxoplasma gondii, Inc: Principles and Practice of Infectious Diseases, G.L. Mandell, J.E. Bennet, R. Dolin, eds., Churchill Livingstone Publ., Fourth edition, p. 2455-2475 (1995)A. Bondiolo et al. ELISA for Toxoplasma antibodies. Inc: Immunoenzyme Assay Techniques, R. Malvano ed.,M. Nijhoff Publ. (1980)M.E. Camargo et. al. Immunoglobine G and immunoglobulin M enzyme-linked immunosorbent assay and defined toxoplasmosis serological patterns. Inf. Immun., 21:55 (1978)Y. Carlier et al. Evaluation of the enzyme-linked immunosorbent assay (ELISA) and other serological tests for the diagnosis of toxoplasmosis. Bull. World Health Organization, 58 (1): 99 (1980)

Additional Information

Name Toxoplasma gondii IgG quantitative
Related Product Names Toxoplasma gondii IgG ELISA
Molecular Weight 0.5
Datasheets / Downloads GWB-170153 Datasheet
Storage The reagents are stable up to the expiry date stated on the label when stored at 2...8 °C.
Intended Use Research Use Only