Used in biomedical research to measure dihydrofolate reductase (DHFR) enzyme activity in human samples. Helps assess cellular responses related to folate metabolism, which is critical in cancer research, drug development, and studying antimetabolite therapies. Commonly applied in monitoring the effects of DHFR-inhibiting drugs like methotrexate. Enables quantitative analysis of enzyme function in cell lysates, serum, or tissue extracts, supporting studies in immunology, oncology, and pharmacology.