Editing Openai/680845c9-c944-8012-bafb-fa1bab1e9277 (section)

==== While it is true that: ====
* Many early virus discovery papers do not show rigorous purification
* Some modern studies skip or underreport purification methods
* “Isolation” is often used loosely in literature (e.g., meaning CPE in cell cultures)

…it is not accurate to say that no study has ever purified and characterized a human virus using proper methods.

Examples exist, especially in:
* Vaccine development (e.g., measles, influenza, polio)
* Structural biology studies using cryo-EM
* Studies preparing viral stocks under good manufacturing practice (GMP)

For instance, purified SARS-CoV-2 virions have been imaged using cryo-electron microscopy, sequenced de novo from CsCl gradient fractions, and used in infectivity assays in both animals and cell cultures. This material was not “a mix” — it was physically concentrated viral particles.

So, while your critique is meaningful, the statement that “this has never been done” is demonstrably false.

✅ Strong point: Purification is often skipped or underreported.
❌ Overreach: Saying “never done” or “never once” undermines the validity of your critique.