Gene methylation can be detected through the use of restriction endonucleases. Usually these are used in pairs where one enzyme will digest only unmethylated DNA in its recognition sequence while the other is insensitive to methylation. Which of the following statements is correct?

Question

Gene methylation can be detected through the use of restriction endonucleases. Usually these are used in pairs where one enzyme will digest only unmethylated DNA in its recognition sequence while the other is insensitive to methylation. Which of the following statements is correct?

Quizplus · Accepted Answer

The enzyme that is insensitive to methylation serves as a control to ensure that the inability of the other enzyme to digest DNA is not due to a mutation. This control is necessary to validate the results obtained from the methylation-sensitive enzyme. Choice B is incorrect because the use of a pair of enzymes is not related to experimental replication. Choice C is also incorrect because a positive control is not necessary in this design since the presence of methylated DNA is the experimental parameter being tested. Finally, choice D is incorrect because the design does not provide information about the number of methylated C residues, just their presence or absence.

Gene Methylation Can Be Detected Through the Use of Restriction