What happens to protein migration in electrophoresis as buffer ionic strength increases?

What happens to protein migration in electrophoresis as buffer ionic strength increases?

• A. It speeds up
• B. It slows down
• C. It remains unchanged
• D. It varies significantly

Answer: (B)

In electrophoresis, when the ionic strength of the buffer increases, there is a corresponding increase in the overall conductivity of the medium. Higher ionic strength leads to a more significant presence of charged ions in the solution, which can shield the charges on the proteins. This phenomenon, known as electrostatic shielding, reduces the net charge that proteins experience in the electric field. As a result of this shielding, the proteins become less responsive to the electric field applied during electrophoresis, which causes their migration through the gel matrix to slow down. The increase in ionic strength not only affects protein migration speed by altering the electrostatic interactions but can also affect the viscosity of the buffer, further contributing to a decrease in migration speed. Therefore, as the ionic strength of the buffer increases, the migrations of the proteins in electrophoresis are slowed down, making this conclusion accurate.

In electrophoresis, when the ionic strength of the buffer increases, there is a corresponding increase in the overall conductivity of the medium. Higher ionic strength leads to a more significant presence of charged ions in the solution, which can shield the charges on the proteins. This phenomenon, known as electrostatic shielding, reduces the net charge that proteins experience in the electric field.

As a result of this shielding, the proteins become less responsive to the electric field applied during electrophoresis, which causes their migration through the gel matrix to slow down. The increase in ionic strength not only affects protein migration speed by altering the electrostatic interactions but can also affect the viscosity of the buffer, further contributing to a decrease in migration speed.

Therefore, as the ionic strength of the buffer increases, the migrations of the proteins in electrophoresis are slowed down, making this conclusion accurate.