PCL(5k)-PEG(3k)-FITC is a biodegradable block copolymer with FITC dye. The polymer is amphipathic and can form micelles upon dispersion in water. The hydrophobic polycaprolactone (PCL) can be used to encapsulate hydrophobic drugs while the hydrophilic PEG not only provides protection against degradation but also provides "stealthy behavior" which is very crucial in vivo for long blood circulation and targeted delivery. Reagent grade, for research purpose.