Which immunological technique uses tagged antibodies to detect specific antigens?

The correct answer is the immunofluorescence technique, which utilizes tagged antibodies to identify specific antigens. In this method, antibodies are labeled with fluorescent dyes, allowing for visualization of antigen-antibody interactions under a fluorescence microscope. This approach is commonly used in diagnostic medicine and research to detect and localize proteins in cells and tissues.

Immunofluorescence can provide critical information about the presence and distribution of antigens within cellular structures, making it a powerful tool in understanding diseases such as infections, autoimmune disorders, and cancers. The specific binding of the labeled antibodies to their corresponding antigens confirms their presence and enables researchers and clinicians to gain insights into the pathophysiology of various conditions.

While techniques such as Western blot, radioimmunoassay, and enzyme-linked immunosorbent assay (ELISA) also involve antibodies for detecting antigens, they utilize different labeling systems and detection methods. Western blot primarily focuses on separating proteins by size before transferring them to a membrane and detecting them with antibodies, but it does not directly involve fluorescent tagging for visualization. Radioimmunoassay employs radioactive isotopes instead of fluorescent tags, and ELISA commonly uses enzyme-linked antibodies that produce a color change upon substrate addition for detection. Each