Which technique separates serum proteins by electrical charge at a pH of 8.6?

Which technique separates serum proteins by electrical charge at a pH of 8.6?

• A. Electrophoresis
• B. Gel filtration
• C. Isoelectric focusing
• D. Chromatography

Answer: (A)

Separating serum proteins by electrical charge at a fixed alkaline pH is accomplished by electrophoresis. In this technique, proteins bear net charges in the buffer, and when an electric field is applied, they migrate toward the electrode with opposite charge. At pH 8.6, most serum proteins carry a negative charge and move toward the positive electrode, with their speeds depending on how much charge they have and their size, producing distinct bands that reflect different protein fractions. This focus on charge in a controlled pH environment is what makes electrophoresis the right answer. Gel filtration separates by size, isoelectric focusing separates by isoelectric point in a pH gradient, and chromatography is a broad method that can separate by various properties.

Separating serum proteins by electrical charge at a fixed alkaline pH is accomplished by electrophoresis. In this technique, proteins bear net charges in the buffer, and when an electric field is applied, they migrate toward the electrode with opposite charge. At pH 8.6, most serum proteins carry a negative charge and move toward the positive electrode, with their speeds depending on how much charge they have and their size, producing distinct bands that reflect different protein fractions. This focus on charge in a controlled pH environment is what makes electrophoresis the right answer. Gel filtration separates by size, isoelectric focusing separates by isoelectric point in a pH gradient, and chromatography is a broad method that can separate by various properties.