What is the smallest observable object

Resolution limits

 

 

  • Structures up to a size of 0.2 mm or less can be seen with the naked eye.
    e.g. fleas, giant amoeba, large plant cells (inside wall of paprika ~ 5mm)
  • A magnifying glass or microscope is required for smaller objects. With a light microscope, structures up to a size of 500 nm can be resolved, with video microscopy or darkfield even up to 50 nm.
    This means that practically all cells of animals, fungi and plants and most of their organelles become visible. Most of the bacteria are also visible.
    eg: chloroplasts, red blood cells, mitochondria, bacteria, cilia
  • For orders of magnitude below 500 nm, resolution is only possible with an electron microscope. The lower limit for electron microscopes is around 0.5 nm. With special and extremely powerful electron microscopes, however, individual atoms can even be created.
    E.g. viruses, cilia, mycoplasmas, microtubules, ribosomes, DNA double helix, H2O molecule