Question

Which one of the following statements is not true regarding gel electrophoresis technique?

• A. The process of extraction of separated DNA strands from gel is called elution
• B. The separated DNA fragments are stained by using ethidium bromide
• C. The presence of chromogenic substrate gives blue coloured DNA bands on the gel
• D. Bright orange coloured bands of DNA can be observed in the gel when exposed to UV light

Answer 1

The Correct Option is C

To determine which statement is not true regarding gel electrophoresis, let's analyze each option:

1. The process of extraction of separated DNA strands from gel is called elution - This statement is true. Elution refers to the process of extracting specific molecules from a gel during electrophoresis.
2. The separated DNA fragments are stained by using ethidium bromide - This statement is true. Ethidium bromide is a common fluorescent dye used to stain DNA fragments during electrophoresis.
3. The presence of chromogenic substrate gives blue coloured DNA bands on the gel - This statement is not true. In gel electrophoresis for DNA, chromogenic substrates are not typically used to visualize DNA bands; instead, dyes like ethidium bromide result in fluorescing colors under UV light, usually orange or other colors, not blue.
4. Bright orange coloured bands of DNA can be observed in the gel when exposed to UV light - This statement is true. When ethidium bromide stained DNA is exposed to UV light, it emits a bright orange fluorescence.

Thus, the incorrect statement regarding the gel electrophoresis technique is "The presence of chromogenic substrate gives blue coloured DNA bands on the gel".