Microscopy required practical

"Use a light microscope to observe, draw and label a selection of plant and animal cells. A magnification scale must be included."

Cells and their structures are too small to be seen with the naked eye, so a microscope is needed to view them. Here’s how to prepare a slide to observe under a light microscope:

1. Cut a thin section of the specimen to allow light to pass through.

2. Using forceps, place the thin specimen on a microscope slide.

3. Add a drop of stain (e.g., iodine solution for plant tissue) to make cell parts, which are usually colourless, more visible.

4. Carefully place a cover slip over the specimen, lowering it gently to avoid trapping air bubbles.

5. Place the slide on the microscope stage. Start with the lowest magnification lens. While looking from the side, use the coarse focus wheel to bring the slide close to the lens, but without touching. Then, look down the eyepiece and adjust the focus:

   • Use the coarse focus wheel first to lower the slide and bring the image into view.

   • Refine the focus with the fine focus wheel.

   • For higher magnification, switch to a higher magnification lens and fine-tune the focus with the fine focus knob.

Additional practical skills

When making a biological drawing from your microscope observations, follow these guidelines:

• Use a sharp pencil for clear lines.

• Do not colour or shade the drawing.

• Draw with continuous lines that do not overlap.

• Keep all parts of the drawing to scale.

• Label all identifiable structures clearly.