MCQ for Agarose gel electrophoresis

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Question 1: Which of the following statements about agarose gel electrophoresis is False?
  • INCORRECT. Please try again.
  • INCORRECT. Please try again.
  • CORRECT. The statement is false because DNA is negatively charged which will migrate towards the positive charged end of the gel.
  • INCORRECT. One of the statements is false.
Question 2: Which of the following is the most preferred buffer condition for agarose gel electrophoresis?
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  • CORRECT! DNA will migrate through the gel towards the positive electrode since DNA has a strong negative charge at neutral pH.
  • INCORRECT. Please try again.
Question 3: Which of the following factors will not affect the rate of migration of DNA in agarose gels?

  • CORRECT! Concentration of DNA will not affect the rate of its migration.
  • INCORRECT! An increase in gel concentration causes the migration rate to decrease.
  • INCORRECT! An increase in voltage causes the molecules to migrate faster through the gel. However, the resolution will decrease at high voltage and there is a risk of melting the gel due to increased heat.
  • INCORRECT! Different conformations of the same DNA affect the effective size of the DNA. For example, different forms of a plasmid will migrate at different rates—closed circular form migrates faster than linear form. To avoid this problem, linear molecules are usually analyzed.
Question 4: If 2% (w/v) of agarose in gel is used, what is the effective separation size range of double-stranded DNA?
  • CORRECT! 2% agarose gel is used to separate double-stranded DNA molecules of size between 0.1 and 3 kb.
  • INCORRECT! To separate double-stranded DNA molecules of size between 0.5 and 7 kb, gels containing 0.9% agarose will be used. Please try again.
  • INCORRECT! To separate double-stranded DNA molecules of size between 1 and 20 kb, gels containing 0.6% agarose will be used. Please try again.
  • INCORRECT! To separate double-stranded DNA molecules of size between 5 and 60 kb, gels containing 0.3% agarose will be used. Please try again.
Question 5: Ethidium bromide is a stain that specifically binds to DNA or RNA and appears _______ if viewed under ultraviolet light.
  • INCORRECT. Please try again.
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  • CORRECT! The UV light excites the ethidium bromide and causes it to fluoresce orange.
  • INCORRECT. Please try again.