English
Karnataka Board PUCPUC Science 2nd PUC Class 12

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?

Advertisements
Advertisements

Question

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?

Short/Brief Note
Advertisements

Solution

The reasons are as follows:

  1. DNA sample that was loaded on the gel may have got contaminated with nuclease (exo-or endo-or both) and completely degraded.
  2. Electrodes were put in opposite orientation in the gel assembly that is anode towards the wells (where DNA sample is loaded). Since DNA molecules are negatively charged, they move towards anode and hence move out of the gel instead of moving into the matrix of gel.
  3. Ethidium bromide was not added at all or was not added in sufficient concentration and DNA was not visible.
shaalaa.com
  Is there an error in this question or solution?
Chapter 11: Biotechnology : Principles and Processes - SHORT ANSWER [Page 79]

APPEARS IN

NCERT Exemplar Biology Exemplar [English] Class 12
Chapter 11 Biotechnology : Principles and Processes
SHORT ANSWER | Q 8. | Page 79

RELATED QUESTIONS

Why is the enzyme cellulase needed for isolating genetic material from plant cells and not form the animal cells?


Collect 5 examples of palindromic DNA sequences. Better try to create a palindromic sequence by following base-pair rules.


Explain briefly:

Restriction enzymes and DNA


How does restriction endonuclease function?


Restriction enzymes ______.


'Restriction' in restriction enzyme refers to


Which of the following statements does not hold true for restriction enzyme?


Would you choose an exonuclease while producing a recombinant DNA molecule?


How does one visualise DNA on an agarose gel?


CTTAAG
GAATTC

  1. What are such sequences called? Name the enzyme used that recognizes such nucleotide sequences.
  2. What is their significance in biotechnology?

What is elution?


State the importance of elution in this process.


What are the protruding and hanging stretches of DNA produced by these restriction enzymes called? Describe their role in the formation of rDNA.


State the principle involved in separation of DNA fragments using gel electrophoresis.


Identify the activity of endonuclease and exonuclease in the given image.


Hind II always cuts DNA molecules at a particular point called recognition sequence and it consists of ______.


In the standard nomenclature convention for restriction endonucleases, what do the second and third letters signify?


In the restriction endonuclease EcoRI, what do the letter 'R' and the Roman numeral 'I' represent?


How are separated DNA bands visualized following agarose gel electrophoresis?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×