The colors are added in, of course, with it being an electron microscope image. Another picture:

  • @Insolentjellyfish
    20•9 hours ago

    At very rough estimate, I would guess a 30 gauge needle. They have an outer diameter of .31 mm. A blood cell is about 7 micrometer across. It looks like you can fit more a smidge fewer than 50 cells across the thickest part of this needle. Cheers!