Lab technique to document implication of a virus in a disease? - (Apr/07/2015 )

Hey guys,

I'm a medical student who's starting to do research and who has a very narrow understanding of cell biology techniques; for that matter I have a rather basic/general question! Let's say we have some disease with a suspected viral cause. Since the virus is not known at this point (i.e we cannot just test for specific antigens since we have no idea what we're facing), what is the go-to technique that will allow us to determine a viral origin? 

Thank you very much for your responses!

one way might be to culture cells suspected of being infected. collect the medium, filter out bacteria and larger then use the collected medium to infect a clean cell culture.

The classic way to do this is to fulfil Koch's postulates.