Every dilution series I do still blows my mind 🤯:

• Get a bit of snot on a swab
• Extract into 1ml
• Take the tiniest droplet (2µl) - is it there?
• Dilute 16x
• Repeat 4 more times!!
• And STILL, PCR can find and make billions of copies of the virus RNA from my nose!!

All together I diluted that bit of snot around a million times and still have no trouble finding (and, if I want, reading on a sequencer) millions of bases of DNA and RNA from my own genome and a huge variety of different microbes living in my nose.