The DNA fragments separated on an agarose gel can be visualised after staining with
(a) bromophenol blue
(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.