03. Preparation and scientific drawing of a slide of onion cells

  • 01:15 What do air bubbles look like under the microscope?
  • 01:32 What cell structures do you observe?
  • 01:51 What units will you use to record the cell size?
  • microscope fitted with an eye piece graticule

  • microscope slide and cover slip

  • onion

  • paper towel

  • scalpel

  • white tile

  • mounted needle

  • iodine-potassium iodide solution

  • forceps

Hazard Risk Control measure

Iodine-potassium iodide solution - Irritant

Contact with eyes and skin

Eye: flood with tap water (10min) Skin: drench with water. Flood with tap water (10min)

Microscope slide and cover slip - sharp if broken

Cuts to skin

Care when using so as not to break. If breakage occurs, sweep up and dispose of broken glass carefully.


Cuts to skin

Cut downwards and away from body, onto a white tile