Objective:To establish a new method for assessing fatty acid uptake of peripheral tissues in animals by using the fluorescence labeled long chain fatty acid

and to provide a new way to study fatty acid metabolism in vivo. Methods:The fluorescence intensity of the liver and adipose tissue was observed under a fluorescence microscope after intraperitoneal（ip）or intravenous（iv）injection of Dipyrromethene Boron Difluoride fluorescence labeled fatty acids analog（BODIPY FL C16） in mice. While the relative fluorescence intensity of the serum

liver and adipose tissue was detected with a microplate reader. Results:Enhanced fluorescence intensity was observed in the serum[ip（32 096±2 053）RFU;iv（22 933±2 430）RFU]

liver[ip（40.90±5.08）RFU/mg;iv（25.70 ±6.53） RFU/mg] and adipose tissue [ip（576 ±90） RFU/mg;iv（4.990 ±0.586） RFU/mg] after both ip and iv injection of BODIPY FL C16（P=0.000）. The relative fluorescence intensity in the peripheral tissues was positively correlated with the concentration of the injected BODIPY FL C16（P=0.000）. Besides

the BODIPY FL C16 after ip injection could maintain metabolically stable between 30 to 100 min. Conclusion:A new method for investigating the fatty acid uptake in vivo by using fluorescence labeled fatty acid is successfully established. This method is stable

reproducible and can accurately reflect the ability of peripheral tissues to uptake the fatty acid.