Why have enzyme immunoassays replaced radioimmunoassays?

Enzyme immunoassays have become more widely utilized than radioimmunoassays primarily due to the associated hazards and regulatory concerns tied to the use of radioactive materials. Radioimmunoassays, while historically significant, involve the handling and disposal of radioactive substances, which presents safety risks to laboratory personnel and requires strict regulatory compliance.

In contrast, enzyme immunoassays utilize enzymes as labels for the detection of antigens or antibodies, significantly reducing the health risks and simplifying regulatory requirements. As a result, laboratories can operate with less concern about environmental and personal safety, making enzyme immunoassays a more favorable choice in modern clinical settings.

While factors such as speed, sensitivity, and specificity are important considerations when choosing an assay method, the concerns regarding safety and regulatory compliance are pivotal reasons for the transition to enzyme-based methods.