top of page

Advances in scientific understanding often rely on developments in technology and technological advances are often linked to scientific discoveries.

Parts of a Microscope

Identify key parts of a light microscope. 

BIO [7-8} Parts of a microscope (DIAGRAM).png

HOOK: Zoom in​

​

HOOK: Zoom In
(Thinking Exercise)

By the end of this section, you should be able to:
 

  • LG1 - Identify key parts of a light microscope. 
    ​

  • LG2 - Use microscopes and digital technology to observe the microscopic world. 
     

  • LG3 - Explore and outline how a light microscope alters the view of a specimen with regards to FOV, magnification, and image orientation (impacting slide movement/position). 
     

  • LG4 - Create wet mount microscope slides.
     

  • Review & Consolidation

How to use a light microscope

Use microscopes and digital technology to observe the microscopic world. 

​

STEP 1: Prepare the Microscope

  • Carry the microscope with two hands; one on the arm and one on the base.

  • Place the microscope on a stable surface.

  • Plug into power and turn on the light source if it's not built into the microscope.
     

STEP 2: Preparing the specimen slide

  • Place your specimen slide onto the microscope stage.

  • Use the stage controls / clips to move the slide around, centring the specimen over the light source.
     

STEP 3: Focusing the microscope

  • Start with the lowest magnification objective lens.

  • Look down the ocular lens to view specimen

  • Use the coarse focus knob for initial focusing, then fine-tune with the fine focus knob.

  • Rotate the nosepiece to switch to higher magnifications for more detail.

  • Gradually move from low to high magnification for clearer images.

  • Adjust the condenser to control the amount of light.
     

STEP 4: Clean Up

  • Turn off the light source and unplug microscope.

  • Lower the stage and remove the slide.

  • Return the microscope to its storage position, cover it to prevent dust, and secure any accessories.

Exploring light microscope

Explore and outline how a light microscope alters the view of a specimen with regards to FOV, magnification, and image orientation (impacting slide movement/position). 

Through the lens of a microscope, the unseen becomes visible, and the intricate beauty of the small unveils the grandeur of the universe hidden in the minuscule.

ACTIVITY 1: Exploring light microscopes

​

Exploring Microscopes

Practical learning activity 

FORMATIVE ASSESSMENT 1: Microscopes

​

Microscopes

(Formative Assessment)

Microscopes

(Answer Key)

Field of View (FOV):

  • The field of view is the area visible through the microscope lens at any given magnification.

  • As you increase magnification (moving to higher-power objective lenses), the field of view typically decreases. This means you see less of the specimen but in more detail.

  • Conversely, lower magnification provides a larger field of view, allowing you to observe a broader area of the specimen.

​

Magnification:

  • Magnification refers to the increase in the apparent size of the specimen.

  • Light microscopes have multiple objective lenses with different magnification levels. You can switch between these lenses to observe the specimen at various magnifications.

  • Higher magnification allows for more detailed examination of smaller structures within the specimen.

  • The total magnification viewed through a light microscope can be determined by multiplying the ocular lens magnification (usually 10x) with the magnification of the objective lens (i.e. 4x, 10x or 40x).

 

BIO [7-8] Field of View (DIAGRAM).PNG
BIO [7-8] Total Magnification (DIAGRAM).PNG
BIO [7-8] Total Magnification (EXAMPLE).PNG

Image orientation (impacting slide movement/position):

  • A microscope uses mirrors which change the viewing orientation of a specimen.

  • Using a light microscope, the specimen will typically appear upside-down and back-to-front.

  • This reversed image orientation makes moving the microscope slide difficult when viewing the image as everything is backwards.

This is actually the letter 'a' not 'g'.

BIO [7-8]_Microscope_The letter 'a'.jpg

Creating Wet Slides

Create wet mount microscope slides.

Wet Mount Microscope Slide:

A wet mount microscope slide is a slide preparation technique used to observe living organisms or specimens in a liquid medium under a microscope. It involves placing a specimen in a drop of liquid on a slide, covering it with a cover slip, and sealing the edges to prevent drying.

ACTIVITY 2:
Creating Wet Slides

​

Creating Wet Slides

Practical learning activity 

Creating a Wet Mount Slide to View Onion Cells:

BIO [7-8] Onion Slides (MATERIALS).PNG

STEP 1: Cut onion into chunks. Use tweezers or a toothpick to place a small, thin sheet of onion on the centre of a microscope slide.
 

STEP 2: Add a drop of water or iodine onto the onion sheet using a pipette or dropper.
 

STEP 3: Carefully lower a cover slip onto the onion sheet, avoiding air bubbles.
 

STEP 4: Gently press down on the cover slip to spread the onion cells and remove excess fluid.
 

STEP 5: Wipe away any excess water around the edges using a tissue.
 

STEP 6: Place the slide on the microscope stage and observe the onion cells under low and high magnifications.

Creating a Wet Mount Slide to View Pond Water:

Can you "catch" the following things:

  • Tardigrade

  • Amoeba

  • Paramecium

  • Euglena

  • Mosquito larvae

BIO [7-8] Pond Wet Mount (MATERIALS).PNG

STEP 1: Collect a small sample of pond water using a dropper or pipette.
 

STEP 2: Place a drop of pond water in the centre of a clean microscope slide. Do NOT add dye as this may harm living organisms in the sample.
 

STEP 3: Gently lower a cover slip onto the water drop, avoiding trapping air bubbles.
 

STEP 4: Allow the cover slip to settle and spread the pond water.
 

STEP 5: Remove excess water from the edges using a tissue.

​

STEP 6: Place the slide on the microscope stage and observe the microscopic life present in the pond water under different magnifications.

Review & Consolidation

Reflect on your achievement of the learning goals. 
 

LG1 - Identify key parts of a light microscope. 
​

LG2 - Use microscopes and digital technology to observe the microscopic world. 
 

LG3 - Explore and outline how a light microscope alters the view of a specimen with regards to FOV, magnification, and image orientation (impacting slide movement/position). 
 

LG4 - Create wet mount microscope slides.

FORMATIVE
ASSESSMENT 4:
Using Microscopes
 

Using Microscopes

(Formative Assessment)

Using Microscopes

(Answers)

bottom of page