Dr. Duncan Clark
Duncan at nospam.demon.co.uk
Mon Jun 12 10:27:17 EST 2000
In article <Pine.LNX.4.21.0006121429400.777-100000 at mailhost.tifr.res.in>
, Gurumurthy D S <gmurthy at tifr.res.in> writes
> I need some help with DNA mobility shift expts. I have seen that
>one of the components of the reaction mixture is poly dI-dC. I would like
>to know a few things about it.
> 1. It it a repeat of dI-dC like ICICICICICIC......?
It depends on how it is written. Poly[d(I-C)] should be as you have put
it above ICICICIC etc.
but poly (dI).(dC) will be dI on one strand and dC on the other. These
should then anneal:
5' ... IIIIIIIIIIIIIIIII ...3'
3' ... CCCCCCCCCCCCCCCCC ...5'
> 2. How long is the polymer that is used in expts?
> 3. Does the polymer has to be a double stranded or single stranded
> will do?
It will be ss or ds DNA depending upon type of polymer.
> 4. Can a polymer synthesized be used directly in the expts or is
> there any pretreatments to be done before use?
>From over 20 years ago (that makes me feel really old!) I have vague re-
collections of denaturing then annealing ds polymer.
We used to buy then, from Boehringer or Pharmacia. There may be more
info. In their catalogues (Roche Diagnostics and APB)
Hope that helps.
The problem with being on the cutting edge is that you occasionally get
sliced from time to time....
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