Used in biomedical research to quantify D-Factor (also known as complement factor D) in human biological samples such as serum, plasma, or tissue culture supernatants. This ELISA kit enables researchers to study the role of D-Factor in the alternative pathway of the complement system, which is involved in immune regulation, inflammation, and host defense. It is commonly applied in studies related to autoimmune diseases, kidney disorders, and infectious diseases where complement activation plays a critical role. The assay provides a sensitive and specific method for measuring D-Factor levels, supporting both clinical research and drug development efforts targeting the complement system.