Question

Researchers sometimes use chromatography as a method to separate biomolecules. Why is electrophoresis used and not chromatography for separating DNA molecules?

• A. Chromatography is used only for coloured substances
• B. Electrophoresis is faster when compared to chromatography
• C. DNA is negatively charged and hence can be easily separated using electric charge
• D. Chromatography cannot be performed for separating charged molecules

Answer 1

The correct option is C DNA is negatively charged and hence can be easily separated using electric charge

DNA has an overall negative charge. Therefore if DNA fragments will move towards the positive end, in an electric field. Moving through the gel matrix helps the DNA to be separated on the basis of the size.