HELP!!!white bands on my autoradiogram!

D.L.Clarke dlc22 at
Fri Jan 2 13:37:21 EST 1998

I have performed a DDRTPCR reaction using 33P dATP as the label.

The reaction appears to have worked, because bands can be visualized
when the products are separated on a 6% denaturing polyacrylamide gel.

The bands are of the normal black colour and are present in either
one or both of the lanes, indicating that differential genes have possibly
been amplified.   

However, in the same lanes and in separate lanes clearly visible white
bands can be seen.  My only explanations for this are,

1.  The developing of the blot, after 72hr, was incorrect.
2.  The products do not contain any label.  This seems unlikely as no cold dATP
    was used during the PCR step.

Therefore, has anybody encountered this phenomenon of a negative
autoradiogram and what was the remedy.

Many Thanks

Dave Clarke

Dave Clarke
Department of Plant Pathology
Cornell University
Geneva, NY. 14456

Phone 315-787-2332
Fax   315-787-2389

e-mail dlc22 at

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