Use of DMSO in General PCR - (Feb/10/2014 )

Hi, I am going to run a PCR with DNA of high GC%. I am wondering, how much DMSO I should use to get a decent band in agarose gel? It might be foolish to ask,but can anyone tell me how to prepare a 100% DMSO stock? My thought about this is that if I want to make a 100% DMSO, I would be doing the following-

100% DMSO= 100g of DMSO (powder) in 100ml water

Then, again I am thinking, 100g in 100ml isn't it too much ? How can it be dissolved ? So, here I am guys seeking your help.

Regards

DMSO is  a liquid, so 100% DMSO comes in the bottle. I'd recommend starting at 4-5% DMSO. But my favorite additive is not DMSO,  but 1 M betaine solution, at similar percentages.