Experiment to look at onion cells using a light telescope Experiment Write Up
Jay Wainwright 12C
Forensic Science
Friday 6th September 2013
Experiment; Looking at onion cells using a light microscope.
Apparatus;
- 1x Light Microscope.
- 2x Pipettes.
- 1x Beaker (100 ml).
- 1x Small Onion.
- 1x Knife.
- 1x Forceps.
- 1x Microscope Slide.
- 1x Cover Slip/Glass.
- Water.
- Iodine Solution.
- Marble Tile.
- Plastic Gloves.
- Window/Strong Light Source.
Pre-Practical - Setting Up the Experiment;
Place the onion onto a marble tile. Using a knife, chop the onion into pieces that are roughly 1.5-2 centimeters. Then discard the rest of the onion.
Place the microscope by a nearby window or a suitable light source i.e. a classroom light.
Half-fill a beaker with water and place a pipette into the beaker, at the same time pinch the top of the pipette, this allows the pipette to 'drain' some water from the beaker and into the pipette.
Practical - The Experiment;
With the onion that had been chopped previously, use the forceps to extract/peel off the membrane that is located underneath the outer skin.
Lay the membrane as flat as possible onto the surface of the microscope slide.
Add 1 drop of water and 2 drops of Iodine solution onto the onion membrane.
Place the cover slip on top of the membrane. Ensure that no air bubbles are present - this could results in an inaccurate image when viewing the onion cell through the microscope.
Place the microscope slide onto the microscope stage. Place the microscope stage clips onto the slide. This will prevent the microscope slide from moving during observation.
Ensure that the microscope's lens magnification is at either x10 or x40.
Look through the eye-piece and draw what you can see.
Post-Practical - After the Experiment/Tidying away equipment;
Turn the focusing handle so that the microscope lenses are at the top of the microscope.
Un-clip the microscope clips and place the microscope slide onto the table.
Place the microscope onto the microscope rack.
Separate the cover slip from the
Forensic Science
Friday 6th September 2013
Experiment; Looking at onion cells using a light microscope.
Apparatus;
- 1x Light Microscope.
- 2x Pipettes.
- 1x Beaker (100 ml).
- 1x Small Onion.
- 1x Knife.
- 1x Forceps.
- 1x Microscope Slide.
- 1x Cover Slip/Glass.
- Water.
- Iodine Solution.
- Marble Tile.
- Plastic Gloves.
- Window/Strong Light Source.
Pre-Practical - Setting Up the Experiment;
Place the onion onto a marble tile. Using a knife, chop the onion into pieces that are roughly 1.5-2 centimeters. Then discard the rest of the onion.
Place the microscope by a nearby window or a suitable light source i.e. a classroom light.
Half-fill a beaker with water and place a pipette into the beaker, at the same time pinch the top of the pipette, this allows the pipette to 'drain' some water from the beaker and into the pipette.
Practical - The Experiment;
With the onion that had been chopped previously, use the forceps to extract/peel off the membrane that is located underneath the outer skin.
Lay the membrane as flat as possible onto the surface of the microscope slide.
Add 1 drop of water and 2 drops of Iodine solution onto the onion membrane.
Place the cover slip on top of the membrane. Ensure that no air bubbles are present - this could results in an inaccurate image when viewing the onion cell through the microscope.
Place the microscope slide onto the microscope stage. Place the microscope stage clips onto the slide. This will prevent the microscope slide from moving during observation.
Ensure that the microscope's lens magnification is at either x10 or x40.
Look through the eye-piece and draw what you can see.
Post-Practical - After the Experiment/Tidying away equipment;
Turn the focusing handle so that the microscope lenses are at the top of the microscope.
Un-clip the microscope clips and place the microscope slide onto the table.
Place the microscope onto the microscope rack.
Separate the cover slip from the