What I was suggesting is that if you are fabricating ISCOMs, is there a reason to not use an off-the-shelf saponin? There are many varieties that others have spent time and energy isolating and packaging. Only trying to save you work. If you are looking for novel saponins to use, then of course you'd want to isolate. In that case, I'd have no idea, and I'm sorry to be useless. :)