Advertisements
Advertisements
प्रश्न
Carefully observe the given picture. A mixture of DNA with fragments ranging from 200 base pairs to 2500 base pairs was electrophoresed on agarose gel with the following arrangement.
(a) What result will be obtained on staining with ethidium bromide? Explain with reason.
(b) The above setup was modified and a band with 250 base pairs was obtained at X.
What change(s) were made to the previous design to obtain a band at X? Why did the band appear at position X?
Advertisements
उत्तर
(a) No bands will be obtained as all DNA will be seen in the well only; DNA fragments being negatively charged will not move towards the negative end/cathode. DNA being negatively charged will remain stationed at the positive end/anode end of the agar block.
(b)
- The position of the positive terminal/end/anode and the negative terminal/end/cathode was inter-changed.
- The fragment with the least base pairs will get separated faster and move faster to the anode end.
APPEARS IN
संबंधित प्रश्न
Mention the difference in the mode of action of exonuclease and endonuclease.
DNA fragments separate according to size through?
Which of the given statements is correct in the context of visualizing DNA molecules separated by agarose gel electrophoresis?
In agarose gel electrophoresis, DNA molecules are separated on the basis of their ______.
Which of the following statements does not hold true for restriction enzyme?
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.
How does one visualise DNA on an agarose gel?
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?
Given below is the restriction site of a restriction endonuclease Pst-I and the cleavage sites on a DNA molecule.
\[\ce{5' C - T - G - C - A \overset{\downarrow}{-}{G 3'}}\]
\[\ce{3' G\underset{\uparrow}{-} A - C - G - T - C 5'}\]
Choose the option that gives the correct resultant fragments by the action of the enzyme Pst-I.
How are DNA fragments visualised once they are separated by gel electrophoresis?
