How to Scan a Cell With An Electron Microscope

Human cells, in general, are up to eight microns in diameter. You can view them in two dimensions under a light microscope, but you cannot see their organelles -- cell "organs" -- in great detail. Scanning electron microscopes, or SEMs, are microscopes that offer sub-nanometer resolution, allowing you to view cells in three dimensions and to probe the inside of whole cells, obtaining information about organelles and cell structure.

Things You'll Need

  • SEM
  • Gold-coating machine
  • Drying oven
  • Mounting plates
  • Electrical tape
  • Latex gloves
  • Spatula
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Instructions

    • 1

      Isolate your cell sample. If your cells are growing in a petri dish, for instance, remove cells from the bottom of the dish, centrifuge by spinning the cells at high speed to obtain a cell pellet, and take a cell scraping.

    • 2

      Dry the cell scraping in a drying oven. The cells must be completely dry before placing them in the SEM to avoid damaging the SEM.

    • 3

      Place a small piece of electrical tape on an SEM mounting platform. Wearing latex gloves, gently -- to avoid breaking dead cells -- spread the dry cells onto the electrical tape with a small lab spatula. Place the mounting platform into a gold-coating machine. Coat the cells with gold.

    • 4

      Vent the sample chamber of your SEM. The sample chamber is a compartment containing a "stage," on which you mount your sample. All viewing of a sample takes place by aiming an electron beam within the sample chamber, at the sample, and by obtaining an image from the electrons that bounce off the sample.

    • 5

      Open the chamber and place your mounting platform on the microscope stage. Close the chamber and click "pump," using the software attached to the SEM, to create a vacuum in the chamber.

    • 6

      Switch on the electron beam when the computer notifies you that you have obtained a vacuum. Focus the stage so that the beam is aimed at your sample. Zoom in to view the details of your cells. The SEM creates a real-time video of your cells by constantly aiming an electron beam at them. Electrons bounce off the gold creating a highly detailed image that you can view on your computer screen.

    • 7

      Acquire images of your cells by taking snapshots from different angles and with different scales.

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