Used in immunological research to detect and quantify complement fragment C4b in biological samples. Helps assess activation of the classical and lectin pathways of the complement system. Commonly applied in studies of autoimmune diseases such as systemic lupus erythematosus (SLE), where complement activation plays a key role. Enables researchers to monitor disease progression and evaluate therapeutic interventions targeting the complement system. Suitable for use with serum, plasma, and other biological fluids in mouse models. Provides a reliable, sensitive, and specific method for high-throughput analysis in preclinical research.