Sequencers: I was wondering if anyone out there has seen this problem
(and if
you have, what causes it and how did you solve it):
Sequencing M13 shotgun clones on 377s (we don't see the problem on 373s)
and
the sequence goes along well for 100 to 150 bases or so and then fades
(very
low peak height) only to return with a good peak height about 100 bases
farther down. If our signal intensity is >400, this doesn't cause a
problem,
but if the base signal intensity is <200 we lose some sequence data.
This was a severe problem when I took over the sequencing operation a
couple
of months ago, but new plates and long ranger gels seemed to solve it.
However, this morning, there were about 4 lanes that showed this pattern
(the
rest of the gel was fine, as a matter of fact we had alignable sequence
out to
940 bases on a couple of lanes (most had quality bases out past 750).
Really!)
So, if anyone has any experience with peaks fading out and then coming
back, I
would appreciate hearing some words of widsom on the subject.
TIA
SRLasky
