Q6 of 44 Page 79

How does one visualise DNA on an agarose gel?

DNA is made visible by staining it with Ethidium bromide, which on exposure with UV rays appears to be orange colored bands.


More from this chapter

All 44 →
4

Restriction enzymes that are used in the construction of recombinant DNA are endonucleases which cut the DNA at ‘specific-recognition sequence’. What would be the disadvantage if they do not cut the DNA at specific-recognition sequence?

 5

A plasmid DNA and a linear DNA (both are of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis, plasmid shows one DNA band while linear DNA shows two fragments. Explain.

 7

A plasmid without a selectable marker was chosen as vector for cloning a gene. How does this affect the experiment?

 8

A mixture of fragmented DNA was electrophoresed in an agarose gel. After staining the gel with ethidium bromide, no DNA bands were observed. What could be the reason?