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DNA marker - (Sep/17/2006 )

hi all,

just have a small Qn, what is a DNA marker used on gels? is it also what is called "DNA ladder"? unsure.gif

best regards...


A DNA marker is basically a mixture of DNA fragments of known size and quantity. When a DNA marker (or for that matter any RNA or protein marker) is run through a gel by electrophoresis, the fragments are separated/sorted out by their individual lenghts. Short fragments run faster then longer fragments. So when the gel is stained and view under ultraviolet light, the lane where the marker was loaded has multiple bands, which look like rungs on a ladder. Hence the name.


thanx for your quick reply..