Sample preparation

Dry mount

  • Solid specimens are viewed whole or cut into very thin sections with a sharp blade- sectioning.

  • Specimen is space on centre of slide and cover slip is placed over the sample

  • Hair, pollen and dust insect parts can be viewed whole and muscle tissue or plants can be sectioned and viewed this way


Wet mount

  • Specimens are suspended in a liquid such as water or an immersion oil

  • A cover slip is placed on from an angle

Aquatic samples and other living organisms can be viewed this way


Squash slides

  • a wet mount is first prepared

  • Lens tissue is used to gently press down the cover slip

  • Potential damage to the cover slip can be avoided by squashing the sample between two microscope slides

Good technique for soft samples, such a root tips to observe cell division


Smear slides

  • the edge of a slide is used to smear the sample, creating a thin, even coating on another slide

  • A cover slip is placed over the sample

Good technique for observing blood


Staining- many biological specimens such as cells and tissue sections are relatively colourless. This means that it is difficult to distinguish between different components they are made up of when viewed under a microscope. Staining makes components of the samples more visible as the colourless organelles and structures all absorb stains differently, creating contrast.


Viewing animal cells

  • use clean cotton swab to scrape mouth

  • Swipe cotton swab on centre of microscope slide

  • Add drop of methylene blue solution

  • Add cover slip at angle and touch paper towel to one side of the cover slip

  • Place under a microscope with a 4x or 10x objective lens in position, find cell then switch to higher magnification


Viewing plant cells

  • peel a single layer of onion tissue from an onion using forceps

  • Place on the centre of a microscope slide

  • Add drop of iodine solution

  • Add coverslip at angle and touch paper towel to one side of the cover slip to remove excess solution

Place under a microscope with a 10x or 40x objective lens in position, find cell then switch to higher magnification


Drawing a diagram

  • Title

  • Use at least 50% space

  • Horizontal labels outside diagram

  • No sketching

  • No shading

  • State magnification

  • Correct shape and proportions