> A milliliter seems like actually a lot of blood to get into someone else 1 cm^3 is indeed pretty big. That’s 1,000 little millimetre cubes, and we can detect

> A milliliter seems like actually a lot of blood to get into someone else 1 cm^3 is indeed pretty big. That’s 1,000 little millimetre cubes, and we can detect as few as 50 virions in that space! I will point out though that 1 ml is low for semen (more like 2.5 ml or more).