Primer walking
Overview
 
Primer walking is a sequencing
Sequencing
In genetics and biochemistry, sequencing means to determine the primary structure of an unbranched biopolymer...

 method of choice for sequencing DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

 fragments between 1.3 and 7 kilobases. Such fragments are too long to be sequenced in a single sequence read using the chain termination method. This method works by dividing the long sequence into several consecutive short ones. The DNA of interest may be a plasmid
Plasmid
In microbiology and genetics, a plasmid is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA. They are double-stranded and, in many cases, circular...

 insert, a PCR product or a fragment representing a gap when sequencing a genome.
 
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