To Determine the Isoelectric Point of a Protein, First Establish

Question

To determine the isoelectric point of a protein, first establish that a gel:
A) contains a denaturing detergent that can distribute uniform negative charges over the protein's surface.
B) exhibits a stable pH gradient when ampholytes become distributed in an electric field.
C) is washed with an antibody specific to the protein of interest.
D) neutralizes all ionic groups on a protein by titrating them with strong bases.
E) relates the unknown protein to a series of protein markers with known molecular weights, Mr.

Accepted Answer

The isoelectric point of a protein is the pH at which it carries no net electrical charge. To determine this point, a gel with a stable pH gradient is needed, which can be achieved by distributing ampholytes (molecules with both acidic and basic groups) in an electric field. As the protein moves through the pH gradient, it will eventually reach a point where its net charge is zero, indicating the isoelectric point. The other options (A, C, D, and E) do not directly relate to determining the isoelectric point of a protein.