PCL(1k)-PEG(2k)-BIO is a biotinylation block copolymer which can bind strongly to avidin/streptavidin. The polymer is amphiphilic with hydrophobic block of polycaprolactone (PCL) chemically attached to hydrophilic PEG block. The polymer can be used to encapsulate drugs or therapeutic agents in drug delivery system. Reagent grade, for research purpose.