Used in biomedical research to quantify levels of surfactant protein D in biological samples, particularly in studies related to lung immunity and inflammatory responses. Helps assess pulmonary host defense mechanisms and is applied in research on respiratory diseases such as asthma, COPD, and pulmonary infections. Enables detection of SP-D in bronchoalveolar lavage fluid, serum, and tissue homogenates, supporting investigations into lung injury, immune regulation, and biomarker development.