That‘s how China is able to test millions of people in a short amount of time. It works only when you have low rate of infections. Instead of testing each samp

That‘s how China is able to test millions of people in a short amount of time. It works only when you have low rate of infections. Instead of testing each sample you test e.g. 5. If this pooled sample tests positive, you test each 5 individually again (for a total of 6 tests instead of 5). If the pool tests negative you‘re done and you‘ve only run 1 test instead of 5 individual ones. So you can run the math yourself to see what % of infection rates it makes sense to pool and when not ;)