The Rheumatoid Factor (RF) qualitative test is a blood test used to detect the presence of rheumatoid factor antibodies in the serum. Rheumatoid factor is an autoantibody (usually IgM) that targets the body’s own immunoglobulin G (IgG).

This test is primarily used as an aid in the diagnosis of rheumatoid arthritis (RA) and may also be helpful in evaluating other autoimmune or inflammatory conditions.