DNA Sequencing-HELP

[bio.tamu.edu]

In article <theveno-300695142147 at cc-hsc-k-box20.cc.umanitoba.ca>,
theveno at ccu.umanitoba.ca (Tracy) wrote:

> I am attempting to sequence a 264 bp region.  I am loading the gel  two
> times: the first loading runs for 2.5 hours and then I do the second
> loading and let the gel run for another 2 hours ( ie the first loading runs
> a total of 5.5 hours).  The problem is that  on film the first loading is
> all smeared but the second loading is ok.  I know the gel is ok and my
> samples are ok because the second loading is fine.   I am running the gel
> at constant power 55 W.  Any ideas?    
> 
> Thanks in advance
> Tracy

Tracy,

are you pre-running your gel before you do your first loading?  I always
used to pre-run my gels for half an hour (at 40-45 W constant power)
before loading my samples.  Hope this is of some help.
Kim
(ksnowden at bio.tamu.edu)