PAGE - (Jan/26/2005 )

I have a smole problem... its new and I dont understandit... I get by PCR a STR... everything fine on agarose...till I puit it on PAA (6%) denaturated with urea...

then I dont see anything.... not even the 10bp ledder.... just some smeres on gel...

I have changed the V, I have changed almoust everything, but still I have it...

Can anybody help me PLS!!!!

Thanks

HI

I'm not sure I get the question exactly, but have you cheched your pH for your buffers? Should be around pH 8.0? DNA tends to run smeared if the pH is too high or low, because pH can shear your DNA fragment.

Some loading buffers that have bromophenol blue and xylene cyanol act as pH indicators, alhtough I'm not sure at what pH they change. But if they are anything other than dark blue (for bromophenol blue) and light blue (cyanol), then you should begin to worry!

Hope this helps.