HMW RNA markers

Paraic Kenny paraic at
Tue Apr 10 13:20:53 EST 2001

Hi Albert

I've never seen RNA markers over 10kb - fortunately my transcripts are a
little smaller than that!

It just occurred to me that if you can't get them commercially it may be
possible to make what you need as follows...

Take any RNA ladder with bands between 1kb and 10kb

Treat with Calf Intestinal Phosphatase to get rid of 5' phosphates.

End label with P32

Ligate the mixture with T4 RNA ligase.

This should give you a series of labelled products between 1kb and ??kb
in 1kb increments.

Obviously it would be necessary to titrate the amount of time or ligase
in the ligation rxn to get the optimum products and it may be necessary
to do a long exposure to see the desired bands, but as a last resort it
might be worth a try.

Good luck


Alberto Chinali wrote:
> Does anyone know if RNA markers longer than 10kb are commercialy available?
> I'm getting a specific signal for a long (possibly between 10 and 15 kb)
> mRNA in my Northerns but I have been unable to find any markers with
> fragments exceeding 10kb.
> --
> Ciao
> Alberto Chinali

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