What is primer extension and chromosomal walk technique

Sergio sergioal at bbm1.ucm.es
Mon Apr 2 07:37:30 EST 2001

Justin Doward wrote:

> Try looking up the polymerase chain reaction (pcr) for primer extension
> information, and I think chromosomal walk technique is referring to the way
> in which enzymes (such as dna polymerase etc) move along dna so look up DNA
> replication.

!!??? Where did you find that information???

Primer extension is a technique to find the transcription iniation nucleotide.
Its based on the amplification of the messenger RNA using the retrotranscriptase
(not a PCR enzyme, since none of them are termostable), and comparing the size
of the amplified cDNA with a sequence of the gene (both performed using the same

Chromosome Walking is a technique to clone adjacent fragments of DNA from a
chromosome. There are different methods, based on labelled probes or insertion
of marker genes.

Try any molecular techniques book...


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