Used in bone metabolism research to quantify N-terminal telopeptide fragments of type I collagen in biological samples, serving as a marker for bone resorption. Enables assessment of osteoporosis, monitoring response to antiresorptive therapies, and evaluating bone turnover in clinical and research settings. The ELISA format allows high-throughput, sensitive detection with minimal sample volume. Commonly applied in serum and urine analysis to support studies in endocrinology, rheumatology, and aging-related bone diseases.