Reply to: RE: DNASEQ: strange 377 gel
Lisa Bibbs wrote:
>Ok I know you guru's can help me with this one. Here I sit at 6:30 AM
>tracking my gels and I have a very strange 377 gel. For all but about =
the
>last 10 lanes, there are no bands until around 4000 scans including the
>control. I tried to analyze the control but it says the signal is too
>weak, although it really isn't. I changed the start and peak numbers to
>4000 but no luck.
>
>Any ideas? I've never seen it.
>
>
>Thanks
>Lisa
>
Lisa,
Your description along with a few queries I have received in the past week =
makes me think that a type of fast fade gel problem is coming back to life.=
But first go to the view of the gel image and describe the boundary =
between good signal and no signal. I'm sure it's not a straight line =
because you would have known it was an electrical fluke. Is it a somewhat =
wavy line and the color drops off quickly as you pass over the line? It =
sounds like the bottom left hand side of the gel is gone. =
8K ---------------
| =
Good | =
| =
| =
4K*_*_*_* | =
* | =
BAD * | =
* | =
0K ______*______
Is the horizontal and vertical boundary the same?
If it is a moderately fast drop off of signal you might have the fast fade =
signal quenching problem. Conditions can occur in the gel that by some =
combination the florescence can no longer escape. The conditions can then =
change so the signal reappears. An old file dealing with this is:
http://mbcf.dfci.harvard.edu/Docs/fastfade.html
I don't know if I ever cured it or it just went away but we changed to =
Long Ranger and got a stainless steel dishwasher and it has been gone =
since 1995. Is anyone else seen this recently?
Paul Morrison D830
Molecular Biology Core Facilities
Dana-Farber Cancer Institute
44 Binney Street
Boston, MA 02115
p_morrison@dfci.harvard.edu
http://mbcf.dfci.harvard.edu
phone 617-632-3082
fax 617-632-4814
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Reply to: RE: DNASEQ: strange 377 gel