NEET Zoology Biotechnology Principles and Processes Questions Solved

NEET - 2017

The DNA fragments separated on an agarose gel can be visualised after staining with

(a) bromophenol blue

(b) acetocarmine

(c) aniline blue 

(d) ethidium bromide

(d) The DNA fragments separated on an agarose gel can be visualised after staining with ethidium

bromide. It is intercalating agent and a fluorescent agent. The stained DNA fragments are seen

bright orange coloured band under UV-light.

Thinking process Intercalation is the insertion of molecules between the planar bases of DNA. This

process is used as a method for analysing DNA. Intercalation occurs, when ligands of an appropriate

size and chemical nature fit themselves in between base pairs of DNA. These ligands are mostly

polycyclic, aromatic and planar and therefore often make good nucleic acid stains. Intensively

studied DNA intercalator include ethidium bromide, proflavine, etc.

Difficulty Level:

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