Your results come in two formats:
the sequence file and the chromatogram.
We again must emphasize that the sequence file is virtually *useless* unless you also examine
- The Sequence File:
This is simply a text listing of the sequence obtained from your DNA. It is what's
known as a "flat text file", aka an ASCII file.
You'll automatically receive the sequence file by email when we have completed the
analysis. You can read this file using any standard word processor, or you can import
the sequence into most DNA sequence analysis software packages. The file is a flat
text ('ASCII') file.
PLEASE NOTE that a text file does not necessarily contain accurate sequence! If your
sample is weak or blank, any or all of the bases reported could be completely wrong.
There are many artifacts that can similarly compromise the accuracy of the basecalls.
You MUST examine your chromatogram in order to assess the validity of your results!
- The Chromatogram:
Each sequence generates a four-color chromatogram showing the partially-processed
data from which the machine determined the nucleotide sequence. You should download
your chromatogram from our Data Server. From the Core's Home Page, click on
You will need your PI's login name and the lab password.
Make sure you read the directions provided there. Note especially that these files
are kept on the server for only about 1-2 weeks after sequencing is done! (The exact
time for which files are kept depends on how much space we have on that server.)
PLEASE NOTE: As of 01-Feb-05, we no longer provide hard-copy printouts of
chromatograms. Click here for more information.
the chromatogram file. You need to know which base calls are reliable, which are not, and why
they are not. Without the chromatogram, you simply cannot trust the raw, textual sequence data.
Please note, however, that your own experimental needs dictate whether the sequencing results
you receive are adequate. We cannot edit your sequence, since to do so would require knowlege
of your needs.
Please read Interpretation of Sequencing Chromatograms for further explanation.