Preparing a slide of cheek cells
The total magnification is found by multiplying the magnification of the eye
piece by the magnification of the objective lens ie
total magnification = eyepiece
- Take a clean microscope slide
- Rub a clean cotton bud around the inside of your mouth and then smear it across the middle of the slide.
- Add one drop of water and a drop of methylene blue stain(1)
- Place a cover slip on the drop (at an angle so that there are no air bubbles)
- Squash it down gently using a piece of blotting paper
- Place the prepared slide on the microscope stage.
- Adjust the light source so that it shines through the slide.
- Focus by turning the focus knob so that the lens moves AWAY from the slide(2)
1:The stain is a special dye that helps the nucleus and membrane show up better
2:Tuning the focus knob is sometimes called ‘racking’)
The same procedure can be carried out on the thin skin that can be peeled from an onion. The stain is not needed in this case.