Chemiluminescence immunoassays (ChLIA) from EUROIMMUN use magnetic particles with a coating of antibodies or antigens. It serves as a solid phase to detect specific antigens or antibodies in patient samples using chemiluminescent signals.
Antibody detection by ChLIA
The antigen-coated magnetic particles undergo incubation with diluted patient samples. If a sample contains specific antibodies directed against the antigen, these bind to the antigen-coated magnetic particles. In the next step, there is the addition of an acridinium-labeled antibody (conjugate) which binds to specific antibodies.
Furthermore, the addition of a trigger solution induces a chemiluminescent reaction. The resulting light signal is proportional to the antibody concentration in the patient sample. The light signal lies within the measurement range and the instrument converts it automatically into a concentration.
Antigen detection by ChLIA
The antibody-coated magnetic particles are incubated with the patient sample and an antigen-specific biotinylated antibody. During the incubation, the magnetic particle-coupled antibody, as well as the biotinylated antibody, bind the antigen.
In the next step, the newly added acridinium-labeled ExtrAvidin (conjugate) binds to the biotinylated antibody. The addition of a trigger solution induces a chemiluminescent reaction. The resulting light signal is proportional to the antigen concentration in the patient sample. The light signal lies within the indicated measurement range and the instrument converts it automatically into a concentration.