1997 Volume 13 Issue 6 Pages 925-929
Triblock copolymer surfactants, Pluronic L61 (L61) and Pluronic 25R2 (25R2), consisting of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) were utilized for the extraction of proteins. The extraction was based on phase separation into surfactant-depleted and -condensed phases (an aqueous phase and a surfactant-rich phase) upon warming aqueous solutions of L61 and 25R2. Hydrophilic cytochrome c was not extracted into the surfactant-rich phase in either Pluronics. However, hydrophobic cytochrome b5 was extracted with L61, while not with 25R2. The difference in the extractability of cytochrome b5 and cytochrome c is probably due to the structural difference in L61 and 25R2.