PCR: Band in one lane, streaking in the other..HELP! - (Jul/08/2011 )

Hello all,

We are doing a PCR (1.2KB amplicon)with genomic mouse DNA and a vector to simulate a positive genotyping PCR. Vector is diluted so there is one copy per genome. 50ng of genomic mouse DNA are used.

Our problem is that we get streaking in some lanes, and the specific band in others. Picture attached.

What we have tried:

-New reagents
-New genomic DNA
-New diluted vector
-Fresh TAE to run the gel
-Fresh SYBR gold to stain the gel
-Using a different thermocycler


In the picture, everything is from the same master mix... so we really don't know what to think.

Any help is appreciated!

Try do a gradient dilution of your genomic DNA. I think your genomic DNA is way far too much...

Second what Adrian has said.

Too much DNA.

Adrian K on Fri Jul 8 17:33:10 2011 said:

gt_ameya on Mon Jul 11 12:26:16 2011 said:

Thanks for the response guys.

We have tried a control with just the vector (no genomic),and we still get the hit or miss streaking. We will try less genomic also, but we are know thinking it could be hyper coiling of the vector. We are liniarizing that.

What do you think? Any other ideas?

Thanks a bunch!