Organic solvents as facilitators of polymerase chain reaction.

We have found that in a system utilizing PCR to detect transgenic mice possessing a sheep metallothionein 1a-sheep growth hormone fusion gene, amplification of a 361-base pair (bp) fragment was completely dependent on the presence of organic solvents such as dimethyl sulfoxide, glycerol or polyethylene glycol (PEG). Much lower concentrations of these solvents (ca. 2% for DMSO) were successful as PCR facilitators than have previously been reported