DMSO ((CH3)2SO) is a polar aprotic molecule, which means it's neutral _and_ polar. It's easier for a small, neutral polar molecule like DMSO to pass through the

DMSO ((CH3)2SO) is a polar aprotic molecule, which means it's neutral _and_ polar. It's easier for a small, neutral polar molecule like DMSO to pass through the phospholipid bilayer of your cells than it is for acetate (CH3COO-). The "dimethyl" is not what it's important.