Question

Which statement is incorrect about SDS-PAGE technique?

• A. Separation are run on gel covered plates
• B. SDS is used to denature the samples
• C. Used to separate proteins
• D. It is ion exchange chromatography

Hint:

SDS-PAGE is an electrophoretic molecular-sieving technique based on molecular weight, not an ion-exchange chromatography method.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) is an analytical electrophoretic method for resolving proteins by molecular mass.

Step 2: Detailed Explanation:
In SDS-PAGE:
1. Proteins are denatured by heating with SDS and reducing agents ($\beta$-mercaptoethanol/DTT), imparting a uniform negative charge-to-mass ratio.
2. Polypeptides migrate through a polyacrylamide gel matrix under an electric field, separating strictly according to molecular weight (sieving effect).
3. It is an electrophoretic migration technique, NOT ion exchange chromatography (which is a column liquid chromatographic technique based on ionic binding).

Step 3: Final Answer:
Therefore, the statement that 'It is ion exchange chromatography' is incorrect.