virus theory - catching the viruses by tissue culture

Steven Avery

By virus theory, there are millions of cells burst by the virus, releasing gazillions of new viruses.

If this were true, it would be very easy to "catch" the exact virus (as well as cell debris) from tissue cultures, taken from people ill or deceased. The viral load should all over the tissue cultures. It would not be necessary to do computer formulations of the sequencing, it would all be right there.

There would be great consistency from, say, five such cultures.
It is understandable that autopsies are difficult, due to all the protective measures, but this is simply a tissue culture.

Has this been done? Why not?
Is it avoided because the results do not match the theory?