Question

What is the purpose of the pH gradient in PAGE (Polyacrylamide Gel Electrophoresis)?

A) To separate proteins based on their charge.
B) To separate proteins based on their size.
C) To denature proteins for downstream analysis.
D) To visualize proteins under UV light.

Answer 1

The purpose of the pH gradient in PAGE is to separate proteins based on their charge and size. This is achieved through the use of a gel matrix composed of polyacrylamide and either denaturing the proteins with SDS or performing two-dimensional PAGE. After electrophoresis, proteins are visualized through staining.

Step-by-step explanation:

The purpose of the pH gradient in Polyacrylamide Gel Electrophoresis (PAGE) is to separate proteins based on their charge. In PAGE, the gel matrix is composed of polyacrylamide and can be modified to separate proteins based on their charges at various pH levels as well as their size. This is achieved by either denaturing the proteins with a negatively charged detergent called sodium dodecyl sulfate (SDS) or by performing two-dimensional PAGE. After electrophoresis, proteins are visualized through staining with Coomassie blue or a silver stain.