Observing human cheek cells under a light microscope is a simple way to quickly view a human cell structure. Many educational facilities use the procedure as an experiment for students to explore the principles of microscopy and the identification of cells. Observation uses a wet mount process that is straightforward to achieve by following an effective preparation method. You can replicate the observational experiment at home with any standard light microscope with magnification settings of X-40 and X-100.
Swab the inside of your cheek with the non-sharp end of a toothpick. Place the toothpick at the bottom of the cheek and move the toothpick up horizontally to collect cheek cells. Be careful not to scrape the inside of the cheek too hard because the epithelial lining is delicate.
Place the swabbed end of the toothpick onto the middle of a microscope slide. Add a single droplet of water squeezed from a plastic pipette onto the centre of the slide. Rotate the toothpick in the water to release the human cheek cells.
Add one drop of methylene blue onto the water and cell solution to stain the cheek cells for observation. Position a cover slip at a 45 degree angle just inside the left edge of the solution. Move your fingers down and to the right to place the cover slip over the cheek cell mixture.
Check for tiny air bubbles under the cover slip and lightly push the cover slip downwards to release any air bubbles you find. Place the edge of a paper towel on any solution outside of the cover slip to absorb the excess moisture. Mount the human cheek cell slide on the light microscope viewing platform.
Choose the X-40 magnification setting on the light microscope and look through the viewing lens. Turn the focusing dial to adjust the focus until you see a clear and crisp image. Observe the human cheek cells by looking for irregularly-edged circular structures with a dark centre, or nucleus.
Change the magnification up to X-100 on the light microscope, and refocus the lens for image clarity if necessary. Observe the increased cell detail that the extra magnification provides. Observe the different details inside the human epithelial cheek cell, noting the cell membrane and nucleic structures inside the cell cytoplasm.
Use iodine as an alternative to methylene blue.
Be careful when handling cover slips because they break easily.
Tips and warnings
- Use iodine as an alternative to methylene blue.
- Be careful when handling cover slips because they break easily.