I remember reading Sklanksy and he talks about Isolation raises being far less common in No Limit compared to Limit because the penalty for accidentally isolating against a better hand, particularly a dominating hand can be losing your whole stack. I might sometimes bluff raise here to knock out the limpage or get HU in position and try to c-bet it but the tables I'm playing are very weak tight pf. I'd recommend reading No Limit Holdem Theory and Practice if you havn't as it talks about differences between limit and no limit.