Re: Blank and partail blank runs on DNA Seq (377XL)
Bruce Stanley (bstanley@psghs.edu)
Tue, 17 Aug 1999 23:34:51 -0400
I don't run sequencing gels anymore, but in the "old days" before automated
sequencing, very faint or invisible radioactive bands in the first half of
the gel were often the result of having too high a ratio of normal
nucleotides to terminator dideoxynucleotides, in fact changing this ratio
was exploited to produce longer vs. shorter sequencing "reads" as desired.
Since the principle of competition between incorporation of normal vs.
terminator dye nucleotides at each position is the same in automated
sequencing, one possible cause of your problem could be a change in this
ratio.
>>> <mcada002@mc.duke.edu> - 8/17/99 5:19 PM >>>
We are at our wits end here tryng to solve a DNA sequencing problem.
Problem:
The samples show blank lanes for the first approximately half of the
run,
then start showing up as if normal. <snip>
Millie McAdams/ Judy Phelps
919 684-2652/ 919-684-2405