Project Nano Videos Scale of Things! Cell Size and Scale Some cells are visible to the unaided eye The smallest objects that the unaided human eye can see are about 0.1 mm long. That means that under the right conditions, you might be able to see an ameoba proteus, a human egg, and a paramecium without using magnification. A magnifying glass can help you to see them more clearly, but they will still look tiny. Smaller cells are easily visible under a light microscope. To see anything smaller than 500 nm, you will need an electron microscope. Adenine The label on the nucleotide is not quite accurate. How can an X chromosome be nearly as big as the head of the sperm cell? No, this isn't a mistake. The X chromosome is shown here in a condensed state, as it would appear in a cell that's going through mitosis. A chromosome is made up of genetic material (one long piece of DNA) wrapped around structural support proteins (histones). Carbon The size of the carbon atom is based on its van der Waals radius.
Electron Microscopy Interactive Java Tutorials - Virtual Scanning Electron Microscopy Interactive Tutorials Virtual Scanning Electron Microscopy We have teamed up with award-winning electron microscopist Dr. Dennis Kunkel to produce a series of interactive tutorials that explore various aspects of virtual Scanning Electron Microscopy (vSEM). Use the tutorial below to discover how specimens appear when magnified in the virtual SEM. When the tutorial is first loaded, the specimen is out of focus and brightness and contrast are not optimized. For questions about Scanning Electron Microscopy, email Dr. Contributing Authors Dennis Kunkel - Dennis Kunkel Microscopy, Inc., P. Matthew J. Questions or comments? This website is maintained by ourGraphics & Web Programming Team in collaboration with Optical Microscopy at theNational High Magnetic Field Laboratory.
Amazing Electron Microscope Photos What Type of SEM are we using? How does the SEM Work? Size of the Nanoscale Just how small is “nano?” In the International System of Units, the prefix "nano" means one-billionth, or 10-9; therefore one nanometer is one-billionth of a meter. It’s difficult to imagine just how small that is, so here are some examples: A sheet of paper is about 100,000 nanometers thick A strand of human DNA is 2.5 nanometers in diameter There are 25,400,000 nanometers in one inch A human hair is approximately 80,000- 100,000 nanometers wide A single gold atom is about a third of a nanometer in diameter On a comparative scale, if the diameter of a marble was one nanometer, then diameter of the Earth would be about one meter One nanometer is about as long as your fingernail grows in one second The illustration below has three visual examples of the size and the scale of nanotechnology, showing just how small things at the nanoscale actually are.
What is an SEM?