immunoassayalapú

Immunoassay-based methods, sometimes described as immunoassayalapú approaches, are analytical techniques that detect and quantify substances by exploiting the specific interaction between antibodies and antigens. In these assays, the analyte binds to a corresponding antibody, and this binding is converted into a measurable signal by a labeled reporter such as an enzyme, a fluorescent molecule, a chemiluminescent compound, or a radioactive isotope.

Two main formats predominate: sandwich and competitive immunoassays. In sandwich assays, an antigen is captured between two antibodies, producing a signal proportional to the antigen concentration. In competitive assays, the sample antigen competes with a labeled reference for antibody binding, and signal inversely correlates with the antigen level. The choice of format depends on the size and properties of the target.

Common immunoassay-based formats include enzyme-linked immunosorbent assays (ELISA), radioimmunoassays (RIA), chemiluminescent immunoassays (CLIA), and lateral flow immunochromatographic assays, as used in pregnancy tests and rapid pathogen detection. Immunohistochemistry and immunofluorescence are tissue-based immunoassays used to visualize the distribution of antigens in cells and tissues.

Applications are widespread in clinical diagnostics, including disease screening and therapeutic drug monitoring, as well as in food safety, environmental testing, and biomedical research. The appeal of immunoassay-based methods lies in their specificity, sensitivity, relative speed, and potential for high-throughput or point-of-care use.

Limitations include dependence on high-quality antibodies, potential cross-reactivity, matrix effects that alter signal, and requirements for appropriate controls and standard curves. While many systems use non-radioactive labels, some traditional formats still rely on radioactivity.