Question

Why are primers required in Sanger’s method of DNA sequencing?

Hint:

Primers provide the starting 3-OH end for DNA polymerase to initiate synthesis in Sanger sequencing.

Answer 1

In Sanger sequencing, primers are short, single-stranded DNA fragments serving as the initiation point for DNA polymerase-driven synthesis of a new DNA strand.

• These primers bind to specific sites on the single-stranded DNA template, guaranteeing that synthesis commences at a predetermined location.
• DNA polymerase requires an existing 3-OH group for nucleotide addition; primers supply this crucial group.
• Without primers, DNA polymerase is unable to start DNA strand synthesis, thereby halting the sequencing process.

Consequently, primers are indispensable for the initiation of DNA replication during sequencing.