Creating a cheek cell slide offers a straightforward way to observe human cells under a microscope. This simple preparation allows individuals to explore the basic building blocks of life. It serves as an accessible and engaging experiment for anyone interested in basic microscopy, providing an introductory understanding of cellular structure.
Gathering Your Materials
Gathering all necessary materials ensures a smooth preparation. A clean microscope slide provides the flat surface for cell placement. A coverslip, a smaller, thinner piece of glass, protects the specimen and flattens it for optimal observation. For collecting cells, use a clean, sterile cotton swab or toothpick to gently scrape the inside of the cheek.
A small dropper bottle of sterile saline solution, such as 0.9% sodium chloride, helps suspend the collected cells on the slide. Methylene blue stain, a common biological stain, makes the otherwise transparent cheek cells visible under the microscope. Finally, a microscope capable of 40x to 400x magnification is required to view the prepared slide.
Step-by-Step Slide Preparation
The initial step involves collecting a sample of your own cheek cells. Begin by gently scraping the inside of your cheek several times with a clean cotton swab or toothpick. This action dislodges loose epithelial cells from the lining of your mouth without discomfort. Ensure the swab or toothpick is clean to avoid introducing contaminants to your sample.
Next, transfer the collected cells onto the center of a clean microscope slide. Roll or rub the cotton swab onto the slide to deposit the cells, or gently dab the toothpick end. Add a single drop of sterile saline solution onto the cell sample. This disperses the cells evenly and prevents them from drying too quickly.
After applying saline, add a small drop of methylene blue stain directly onto the cell suspension. Methylene blue is a basic dye that stains acidic components like the nucleus, making cellular structures more discernible. Exercise caution, as the stain can temporarily color skin and permanently stain clothing. Gently lower a coverslip over the mixture at a 45-degree angle, then slowly drop it flat to minimize air bubbles.
Air bubbles under the coverslip can obscure the view. Blot any excess liquid around the coverslip edges with a paper towel. The slide is now ready for examination under a microscope.
Observing Your Cheek Cells
Place the prepared slide onto your microscope stage and secure it with the clips. Begin observation using the lowest magnification objective, typically 40x or 100x, to locate the cells. Focus the microscope carefully using the coarse and fine adjustment knobs until the cells appear sharp. Human cheek cells, also known as buccal epithelial cells, typically appear as flat, irregularly shaped structures with indistinct edges. These cells are generally around 50 to 100 micrometers (µm) in length and width.
At the center of each cell, you should observe a distinct, darker-stained circular or oval structure: the cell’s nucleus. Methylene blue stain highlights this nucleus, making it readily visible. The cytoplasm, the jelly-like substance filling the cell, will appear as a lighter, often pale blue area surrounding the nucleus. The cell membrane itself is too small to be seen with a typical compound microscope, but it defines the cell’s outer boundary.
As you increase magnification, for instance to 400x, the nucleus and overall cell shape become more apparent. You might notice some cells appear folded or clumped together, which is normal for this sample type. Adjusting the light intensity and fine focus will further enhance the clarity of cellular structures. You may also observe much smaller, rod-shaped or spherical blue dots, which are bacteria commonly found in the mouth.