I'm working through my basement refinishing project and am ready to frame walls set out from the poured concrete walls in part of the basement. I have already taped 2' squares of plastic to several locations on all walls and have seen no moisture after several days. (we have had rain/snow during that period, still no moisture on the walls.) I have been in the house 9 years, never a trace of moisture in the basement.

The Question: should I seal these walls before I frame and insulate?

It can't hurt to use a good sealer but I always cover the entire wall with 6 mil plastic before insulating. Be sure your floor plate is pressure treated lumber and your vapor barrier is facing the inside wall surface. Have you considered a radon test before you make this a living space? This product may help for both situations. D-I-Y Deep-Penetrating Sealers for Concrete, Brick, and Masonry

Thanks B1! To clarify, you suggest vapor barrier against wall, frame & insulate, vapor barrier, dry wall?

Kind of, I was thinking batt insulation with its own barrier. Make sure the paper or foil is facing the drywall.