2- ethanesulfomc acid

Dialysis A purified protein is in a Hepes (7V-(2-hydroxyethyl)piperazine-A/ -(2-ethanesulfomc acid)) buffer at pH 7 with 500 mM NaCl. A sample (1 mL) of the protein solution is placed in a tube made of dialysis membrane and dialyzed against 1 L of the same Hepes buffer with 0 mM NaCl. Small molecules and ions (such as Na+, Cl-, and Hepes) can diffuse across the dialysis membrane, but the protein cannot. 

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