Selective precipitation of a protein from a crude extract is MOST effective by which molecule?

Question

Quizplus · Accepted Answer

Ammonium sulfate is commonly used to selectively precipitate proteins from a crude extract based on their solubility at different salt concentrations. By gradually increasing the concentration of ammonium sulfate in a solution, proteins will eventually precipitate out of solution at their isoelectric point or at a specific salt concentration that is unique to each protein. Urea is commonly used for denaturing proteins but does not selectively precipitate them. Sodium dodecyl sulfate and EDTA are commonly used for protein solubilization and metal ion chelation, respectively, but do not selectively precipitate proteins from a crude extract.

Selective Precipitation of a Protein from a Crude Extract Is