PCL(2k)-PEG(1k)-BIO is a self-assembling polymer with polycaprolactone (PCL) as hydrophobic block and PEG as hydrophilic segment. In water, the polymer forms micelles with PCL as core and PEG as shell. The core regions can serve as reservoirs for hydrophobic drugs while the shell protects the core from enzymatic/hydrolysis degradation. The biotin can strongly bind to avidin or streptavidin which can be useful for detection of proteins, nucleic acids and lipids as well as protein purification. Reagent grade, for research purpose.