Arnoud van Vliet arnoud at
Sun Jun 28 18:52:35 EST 1998

Hi Brenda,

you'll have to be give a few more details. Do you get a double band with
every nucleotide? What kind of sequencing: radioactive / non-radioactive? If
you sequence non-radioactive, with a fluorescein labelled primer, then the
double banding might be explained by incomplete labelling of the primer.
When I started doing radioactive sequencing using fluorescein labelled
primers, they were usually incomplete labelled. The non-radioactive
sequencer I bought the primers for didn't work properly at the time, so I
had to do radioactive sequencing. And as the fluorescein group changes the
MW of the primer by about one base, that explained the double bands: one of
the fluorescein-labelled primer, one of the unlabelled primer.

Sorry, I have run out of other explanations with only this information.
Supply the newsgroup with more details and somebody might be able to help


-----Original Message-----
From: J. Hendriks <hendrikb at>
Newsgroups: bionet.molbio.methds-reagnts
Date: 28 June 1998 11:53
Subject: sequencing

Hi there

In my last sequencing gel I saw double bands instead of one. These bands are
not due to a mutation. Does anyone have an explanation. Please respond also
to my e-mail adress: b.hendriks at

Thank you very much.

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