I remember reading somewhere that someone did PCR

I remember reading somewhere that someone did PCR for virus RNA in lung secretions of some sort.

I think the RT-PCR counts the number of viral RNAs so I think they just put a sample in, maybe one nanoliter or microliter or somehting like that, and the machine spits out the number of viral RNAs in the sample.

So if you can get a sample from the tissue, then you just put it in the machine, I think.

Blood tissue obviously easy to get. Maybe lung secretions as well.