BF-170 is a selective tau fiber-binding agent with an EC50 of 221 nM. It demonstrates excellent blood-brain barrier penetration, reaching a concentration of 9.1% ID/g in brain tissue 2 minutes after intravenous injection in mice (with a clearance rate of 0.25% ID/g at 30 minutes). BF-170 can serve as a probe for imaging tau protein pathology in Alzheimer's disease (AD). It plays a significant role in early-stage Alzheimer's disease studies and holds promise for imaging research in tau-related neurodegenerative diseases.