ArcDia™ TPX technique

mariPOC^® test system applies ArcDia™ TPX technique – a separation-free two-photon excitation assay technique developed by Arctic Diagnostics Oy.

The technique applies polystyrene microparticles as solid phase reaction carries for the immunocomplex formation. As a result of the antibody-antigen interactions, three-component immunocomplexes of MAb-Ag-MAb* (monoclonal antibody – antigen – labelled monoclonal antibody) are formed on the microspheres in proportion to the analyte concentration.

The detection of the immunoassay fluorescence signal is carried out by means of two-photon excitation (λ_ex = 1064 nm) from the surface of individual microspheres. Microspheres are trapped into the focus by optical forces of the laser, and the bound and the unbound tracer fractions are separated optically. This means without washes. Both the microsphere signal (specific signal) and the solution background signal (unbound tracer and matrix) are recorded. This allows for efficient compensation of matrix effects.