Which of the following statements about two-dimensional gel electrophoresis are correct? Question 19 options: A) SDS gel electrophoresis and isoelectric focusing both separate native proteins. B) Only SDS gel electrophoresis makes use of the migration of proteins in an electric field C) SDS gel electrophoresis and isoelectric focusing both require a pH gradient D) SDS gel electrophoresis and isoelectric focusing together make up the process of two-dimensional gel electrophoresis

• A)

SDS gel electrophoresis and isoelectric focusing both separate native proteins.

1. C)

SDS gel electrophoresis and isoelectric focusing both require a pH gradient

1. D)

SDS gel electrophoresis and isoelectric focusing together make up the process of two-dimensional gel electrophoresis

Explanation:

A two-dimensional gel electrophotesis separate proteins in two steps by relying on protein's two properties. First, Isoelectric focusing is used to separate proteins in accordance to their isoelectric points (pI). Secondly, the SDS-PAGE electrophoresis method separates proteins based on their molecular weight. The gel requires a pH gradient and potential difference across. In both methods, there is protein migration across the gel. In the first method, proteins migrate through pH gradient until each protein carries no further charge.