In salting-out albumin procedure, high salt precipitates which fraction?

• A. Globulin
• B. Albumin
• C. Both
• D. Neither

Answer: (A)

Salting-out relies on ionic strength to reduce protein solubility. As you increase salt concentration, proteins precipitate in an order based on how soluble they are under those conditions. Globulins are less soluble in high salt solutions than albumin, so they come out of solution first when the ionic strength is raised. That means at a sufficiently high salt level, the fraction that precipitates is globulin, while albumin tends to stay dissolved and can be collected later after adjusting conditions.