A NOTEr It is important to appreciate that when we talk about isolating and purifying a given macromolecule in the ensuing discussion we rarely mean that a single molecule is isolated. rather the goal of these procedures is to isolate a large population of identical molecules from all of the other kinds of molecules in cellA NOTE: It is important to appreciate that when we talk about isolating and purifying a given macromolecule in the ensuing discussion we rarely mean that a single molecule is isolated.rather,the goal of these procedures is to isolate a large population of identical molecules from all of the other kinds of molecules in cell