Method Description

The electrochemiluminescence immunoassay for the in vitro quantitative determination of IgG antibodies to Toxoplasma gondii in human serum is a sandwich test principle. During the first incubation, 6 mcL of sample a biotinylated recombinant T. gondii-specific antigen labeled with a ruthenium complex form a sandwich complex. In the second incubation, streptavidin-coated microparticles are added and the complex becomes bound to the solid phase via interaction of biotin and streptavidin. The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Unbound substances are then removed with ProCell II M. Application of a voltage to the electrode then induces chemiluminescent emission which is measured by a photomultiplier. Results are determined by a calibration curve which is instrument-specifically generated by 2-point calibration and a master curve provided via the cobas link.(Package insert: Elecsys Toxo IgG, Roche Diagnostics GmbH, 02/2022)