The correct answer is option 3: Tuberculosis bacterium. ELISA, which stands for Enzyme-Linked Immunosorbent Assay, is a diagnostic test commonly used to detect the presence of specific antibodies or antigens in a given sample. In the case of tuberculosis, the ELISA test is utilized to identify the presence of antibodies against the bacterium that causes the disease. By detecting these antibodies, healthcare professionals can diagnose tuberculosis and initiate appropriate treatment.
Options 1 (Polio virus) and 2 (AIDS antibodies) are incorrect because ELISA is not commonly employed to diagnose these conditions. Option 4 (Cancer) is also incorrect, as ELISA is not typically used as a primary diagnostic tool for cancer.
It is important to note that ELISA can be used for various other diagnostic purposes, such as detecting allergies, autoimmune diseases, and infectious diseases caused by other bacteria or viruses.