I'm having some problems getting a PCR to amplify a region of mouse tail (& have tried macrophage) genomic DNA, about 800bp. I can get the same PCR to work in the Stem cell DNA used to make the mice and the targetting vector used to make the stem cells but it will not amplify from the genomic DNA.
I have used the same genomic DNA in other PCR reactions and it worked fine. I have also tried genomic DNA from different mice.
I have tried about 10 different primer sets using a Ta gradient with no luck. They ALL worked in the stem cell DNA and vector DNA.