Question

Which of these statements is true?

Select one:

a. Sanger sequencing requires dideoxyribonucleotides instead of standard deoxyribonucleotides

b. All four dideoxyribonucleotides are combined together during sequencing

c. Sanger sequencing requires that the template DNA to be sequenced is single-stranded

d. all the above

e. a and b

Answer 1

D. All the above

Sanger sequencing or chain termination method is also referred to as dideoxynucleotide sequencing because of the use of the specialtypes of ddNTPs. The ddNTPs are different from normal dNTPs due to  the presence of hydrogen group instead of hydroxyl group in dNTPs. Phosphate ester bondcannot be formed between two adjascent nucleotide due to absence of hydroxyl group in ddNTPs. The mucleotide chain cannot synthesis further and so it is called chain termination reaction.