It wasn;t just the predaliens blood that seemed ineffective at the end of the movie, it was all the aliens, and Colin explained why. It has nothing to do with preds being resistant to it (which we saw in AvP the weren't), and if the preds blood did neutralize it it would do as much damage to things because it would have to be a strong base.
and I don't care what the comics say, as they are non-canon.