What is the purpose of the modified bases in DNA sequencing?

What is the purpose of the modified bases in DNA sequencing?

Choose one answer.

a. DNA replication terminates when a modified base is added.

b. They are easily recognized by the computer.

c. They are added to the DNA chain just like the normal bases.

d. All of these.

e. None of these.



PLEASE HELP!What is the purpose of the modified bases in DNA sequencing?
It's d.

The modified bases are fluorescently labelled dideoxynucleotides. They can be incorporated into a growing DNA chain by their 5'-phosphate group (c. - i.e. like normal deoxynucleotides) but they lack a 3'-OH group meaning that no new bases can be incorporated (a.). Since they are fluorescently labelled, the label can be excited by a laser and easily picked up by a computer (b.) to identify the base.

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Yes, sorry, Neil-Rob is right! Amended!What is the purpose of the modified bases in DNA sequencing?
Above answer has it right.



That said, the modified bases are incorporated by virtue of their 5' phosphate groups. They don't have 5' OH groups.What is the purpose of the modified bases in DNA sequencing?
D