[yosito]

I'm not an expert, but I think if a molecule is isolated, it is possible to determine whether or not it is a prion. IIRC, prions are basically misfolded protiens that cause other protiens to misfold, like a corrupted file that passes the corruption on to every copy or derived file until the system crashes. But you can examine them before systemic problems show up. And I believe a prion has to be a protien-like molecule. Again, not an expert.