When holes occur due to high protein concentration in electrophoresis, what is the most appropriate adjustment?

• A. Increase buffer pH
• B. Decrease protein load
• C. Increase gel thickness
• D. Decrease agarose concentration

Answer: (B)

Overloading a gel lane is the main issue here. When protein concentration is too high, the sample becomes very viscous and crowded as it enters and moves through the gel. This creates uneven migration paths and local disturbances in the gel matrix, which show up as holes or voids in the solution front. By loading less protein, the sample can migrate through the gel smoothly, giving a uniform front and clearer bands without those artifacts.

Other adjustments don’t address the root cause. Increasing the buffer pH changes the charge and migration of the proteins but doesn’t fix the physical crowding that creates holes. Altering gel thickness or changing agarose concentration affects resolution or mobility but won’t specifically correct the artifact caused by overloading. The most effective fix is simply to reduce the amount of protein loaded.