No PCR bands with some templates - (Sep/03/2009 )

Hi all
Some of my Genomic DNA samples are not giving pcr product.....there are no protein contamination.....OD is 1.8
right now i am using 10ng/ul of dna
i am unable to find out the reason behind this problem. ...even i did reprecipitation of dna but still no result.
I am wondering if i cud change the buffer to dissolve DNA ,right now i m dissolving it in TE buffer

2. my another query is ...is it possible to dissolve genomic DNA in water

You can use water to dissolve DNA. I use Tris at pH 8; a slightly basic solution dissolves DNA better (DNA is an acid, after all). I do not use EDTA, but whether you need to or not depends on how clean (e.g. free of nucleases) your DNA prep is...

Hi,
Can you tell us your PCR master mixes and cycling condition? Had you optimized your PCR?

Yes, is possible to dissolve genomic dna in sterile water.

are your DNA samples from the same organism?

gebirgsziege on Sep 3 2009, 07:04 AM said:

yes dna are from same organism.......i have isolated it from 1ml blood sampple from cardiac patients.......all condition are optimised as i already done with 10 samples.......
i dont know what to do ........right now i m serially diluting all my dna to 10ng/ul

dede on Sep 2 2009, 11:05 PM said:

to clarify:

some samples are not yielding any product, but separate independent samples are yielding product when assayed with the same primer pair...or one primer pair yields a product, but another primer pair when used with the same gDNA does not yield a product?

i'll assume the former rather than the latter.

are these diagnostics in that you're looking for variations in alleles (e.g. insertions, deletions, CNV etc.)?

if you're not already doing so, you should always run a control PCR rxn along with your experimental rxn's. the control is simply ensuring that your gDNA is of PCR quality...aside from the OD readings, have you looked at your sample on a gel to ensure it is not degraded?