Used in immunological research to detect and quantify complement protein C4 levels in rabbit samples. Helps in studying the activation of the classical complement pathway, immune complex diseases, and inflammatory responses. Commonly applied in biomedical research, especially in models of autoimmune disorders, transplantation, and infectious diseases where complement system involvement is investigated. Provides a reliable, sensitive, and specific method for measuring C4 concentration in serum, plasma, or tissue homogenates, supporting both basic research and preclinical studies.