With today’s sophisticated analytical laboratories procedures, clinical labs can detect very small amounts of DNA present in the blood circulation and in various body tissues. DNA tests are used in medicine to help diagnose diseases such as hemachromatosis or clotting disorders. These diseases are caused by and diagnosed with tests that detect these genetic mutations. Recent research suggests that tests for DNA can also help researchers identify the disease process in various autoimmune diseases, including most connective tissue diseases, primarily rheumatoid arthritis.

According to traditional theory, human DNA is found in the nucleus or in the mitochondria of cells. In the early DNA tests, commonly used today, DNA is extracted from the body’s tissues and cells, amplified, and studied to determine specific genetic markers and mutations present on specific chromosomes. However, new findings show that free DNA (not attached to any of the body’s cells) may be attached to antibodies, primarily autoantibodies, as a DNA-antibody complex. These complexes have been found in the blood circulation of people with several different autoimmune disorders.