The Anti-DS-DNA (anti-double stranded DNA) test is a blood test used to diagnose Systemic Lupus Erythematosus (SLE), a type of autoimmune disorder. This test detects antibodies specifically targeting double-stranded DNA. A positive result for Anti-DS-DNA is strongly indicative of an autoimmune condition, particularly SLE. It is a crucial tool in detecting and diagnosing lupus, helping doctors confirm the presence of the disease and guide treatment decisions.