role of water in PCR - (Dec/06/2012 )
I was wondering if anyone could explain the specific role of water in a PCR reaction. I was wondering if the addition of water could be completely eliminated and instead compensated by adding more template if I had a very low concentration of template.
Depends whether you have your template disolved in water or in yogurt.
Water is the solvent you use to get the final concentrations of the reagents in the desired volume...if you use more diluted DNA or other reagents (Mg2+, primers, buffer) you might end up that you don't need to add any additional water, but that's by chance then, as you cannot change their volume (except DNA often-times).
Anyway there's no need to add additional water as the water can come from any other source, but surely it's much easier to use it to get the desired volume.
Even I was having the same problem of low tempet.Try to evoporate the solvent (water or any buffer your dna is suspended) by heating the tube at around 55-60 C and increase the concentration of your dna. I did it a couple of times and it worked perfectly for my qpcr (:. By this way you retain the same final volume as you used to do before.
PS: make sure that the cap is open when heating