Acridinium esters are commonly used in which type of immunoassay?

Acridinium esters are specifically utilized in chemiluminescence immunoassays due to their unique properties. These compounds can emit light upon undergoing a chemical reaction, which is a vital component in the detection mechanism of chemiluminescent assays. When acridinium esters are coupled to an antigen or antibody, they become part of the immune complex that, upon interaction and subsequent triggering, produces light. The intensity of this emitted light correlates with the concentration of the analyte being measured, allowing for sensitive and quantitative detection.

In contrast, other types of immunoassays, such as radioimmunoassays, rely on radioactive isotopes for detection, while enzyme immunoassays use enzyme-substrate reactions to generate a measurable color change. Fluorescence immunoassays utilize fluorescent labels that emit light upon excitation, differentiating them from chemiluminescence. Thus, the specific application of acridinium esters aligns precisely with the requirements and characteristics of chemiluminescence immunoassays, making this the correct choice.