Question

Which of the following is untrue about DNA sequencing?

(a) It is now routinely carried out using the Sanger method

(b) This doesn’t make use of DNA polymerases

(c) This involves the synthesis of DNA chains of varying length

(d) The DNA synthesis is stopped by adding dideoxynucleotides

I had been asked this question in quiz.

My enquiry is from Genome Sequencing topic in division Genome Mapping, Assembly and Comparison of Bioinformatics

Answer 1

Right choice is (b) This doesn’t make use of DNA polymerases

To elaborate: DNA polymerases are used to synthesize DNA chains. The dideoxynucleotides are labeled with fluorescent dyes, which terminate the DNA synthesis at positions containing all four bases, resulting in nested fragments that vary in length by a single base. When the labeled DNA is subjected to electrophoresis, the banding patterns in the gel reveal the DNA sequence.