ELISAbased

ELISAbased refers to diagnostic and analytical methods that use the enzyme-linked immunosorbent assay (ELISA) principle to detect or quantify target analytes. In these assays, an antigen or antibody is immobilized on a solid phase, and a specific binding partner is revealed by a secondary antibody conjugated to an enzyme. Substrate conversion by the enzyme yields a detectable signal.

Common formats include indirect ELISA (antibody detection with an enzyme-labeled secondary antibody), direct ELISA (antigen detection with a labeled primary antibody), sandwich ELISA (two antibodies capture and detect the antigen), and competitive ELISA (signal inversely related to analyte concentration).

Workflow typically involves coating wells with antigen or antibody, blocking nonspecific sites, applying samples, adding enzyme-labeled detection reagents, substrate incubation, and measuring the signal with a plate reader. Quantification relies on a standard curve generated from known concentrations.

Readouts are usually colorimetric but may be chemiluminescent or fluorescent. ELISAbased assays are widely used in clinical diagnostics, including infectious diseases, hormones, and autoimmune markers, as well as in food safety, environmental testing, and basic research. They are often automated for high-throughput screening and can offer high sensitivity and specificity with appropriate controls.

Limitations include dependence on antibody quality, possible cross-reactivity, matrix effects, and the need for rigorous optimization and standard curves. ELISAbased technology originated with the development of ELISA in the late 20th century and remains a foundational tool in immunodiagnostics and biosensing.