The IFA test is performed by first taking a sample of blood or tissue from the patient. The sample is then placed onto a slide that has been coated with antigens from various types of cells found in the body. If ANAs in the patient’s sample bind to any of these antigens, then fluorescent dye can be added so that they become visible under a microscope. A technician will look for specific patterns formed by these ANA antibodies that indicate which type of autoimmune disease may be present in the patient’s body.