What is the primary advantage of labeled immunoassays compared to unlabeled immunoassays?

The primary advantage of labeled immunoassays is their sensitivity. Labeled immunoassays utilize a detectable marker attached to the antibody or antigen, such as an enzyme or a fluorescent dye. This labeling allows for the amplification of the signal, making it easier to detect even low concentrations of the target analyte in a sample. The presence of the label increases the assay's sensitivity, enabling precise measurements in complex biological samples, which is particularly important in immunology for the detection of antibodies or antigens that may be present at very low levels.

In contrast, unlabeled immunoassays do not rely on such amplification and often require higher concentrations of the target for reliable detection, making them less sensitive overall. While other factors such as simplicity, cost-effectiveness, and speed of results are important considerations in the choice of assay type, they do not generally surpass the improved sensitivity that labeled assays offer when it comes to detecting specific biomolecules.