G.C. wrote:
> I would like to know what is a TRF exactly. (Telomere Restriction
> Fragment). Thank you
It's the length of telomere that is chopped off by a restriction
enzyme. Restriction enzymes come from bacteria, and they chop DNA only
at very specific sequences. These sequences appear at irregular
intervals in most DNA, but the repetitive DNA that telomeres are made
of doesn't have any such sequences. Thus, if you get the DNA out of
cells and let a restriction enzyme chop it up, most of the DNA is
reduced to rather short fragments, but the telomere DNA is left
intact. That means that the length of the longest fragments of DNA is
the length of the telomeres in the cells.
Aubrey de Grey
