Used in immunological research to quantify levels of complement protein C3 in biological samples such as serum, plasma, or tissue extracts. Enables assessment of complement system activation in studies related to inflammation, autoimmune diseases like lupus, and immune complex disorders. Supports research in infectious diseases, transplant rejection, and neurodegenerative conditions by providing a reliable method to monitor C3 concentration changes. Commonly applied in preclinical studies and biomarker validation where complement pathway involvement is under investigation.