Final answer:
Antibody based assays are linked to easy-to-see fluorescent molecules, which allow for the rapid and clear detection of antigens, particularly in the diagnosis of infectious diseases.
Step-by-step explanation:
Antibody based assays, such as immunofluorescence, are methods that involve attaching antibodies to easy-to-see fluorescent molecules. These assays utilize antibody-fluorogen conjugates that, when exposed to light, allow for the rapid and clear detection of antigens. For example, in direct immunofluorescence (DFA), fluorescently-labeled monoclonal antibodies (mAbs) bind directly to the antigens in a sample, such as bacteria in a sputum sample. The fluorescent antibodies enable the visualization of bacteria under a fluorescence microscope, providing rapid detection and diagnosis of infectious diseases. Indirect immunofluorescence (IFA) involves the use of secondary antibodies that recognize and bind to primary antibodies, which are themselves specific to the antigen of interest. Due to the nature of these assays, the correct answer to the question is b. Fluorescent molecules.