I am not science minded but from my understanding is that you cannot isolate a virus you can only replicate it. So they use whatever eye of newt measures needed until they have built an identical replicate of the virus. Those eye of newt measures will have their own RNA/DNA strands in those replications. They could then download that information and send it anywhere across the globe, including to be gained. Gaining would be taking the RNA/DNA strands from other replicated viruses to see if they can achieve whatever goals they are after. So for example if they wanted the corona virus they replicated to be more highly transmissible than they'd take the strand of code they build into their replication of say the measles, a highly transmissible virus and add that code into their code for corona and see where it gets them. If they wanted it to be more deadly than they'd take whatever they added in their replication of Ebola that made it so deadly and they'd add that to the corona virus RNA/DNA sequences. I could be wrong but what I think they mean by isolation and replication of a virus is that they've isolated the actions of a virus and have been able to replicate it.