Used in biomedical research to quantify MUC5AC levels in biological samples such as sputum, bronchoalveolar lavage fluid, and cell culture supernatants. Helps assess mucus overproduction in respiratory diseases like asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis. Supports studies on airway inflammation and mucin regulation. Enables evaluation of therapeutic agents targeting mucus hypersecretion. Widely applied in preclinical research and drug development.