The main terminology that must be exposed is the differentiation between purification and isolation of alleged HIV virus.

These words are frequently considered equivalent, but I considered them differently (and I think the Perth Group uses this terminology too)

Purification: to separate alleged HIV particles from everything else;

Isolation: to demonstrate alleged HIV existence, that is, includes to purify, but involves other steps too, including that the alleged HIV particles replicate.

VIH existence could be also determined with indirect observations, mainly the so-called genome sequencing. So this would be an isolation too.

But there are certain doubts about alleged genome sequencing as a valid method to demonstrate VIH existence (see here).