Cell structure - AQA Preparing biological samples for examination

Organisms are made up of cells. Most organisms are multicellular and have cells that are specialised to do a particular job. Microscopes are needed to study cells in detail.

Part ofBiology (Single Science)Cell biology

Preparing biological samples for examination

Aims of the experiment

  • To stain cells for examination with a light microscope.
  • To examine a range of cells and other structures with a microscope to understand their basic structure.
Image gallerySkip image gallerySlide1 of 3, biological samples for examination, Animal cells Cheek cells

When viewing any slide with a microscope, a small square or circle of thin glass called a coverslip is placed over the specimen. It protects the microscope and prevents the slide from drying out when it’s being examined.

The coverslip is lowered gently onto the specimen. A can be used to hold the specimen in place as the coverslip is lowered. It is important that no air bubbles are trapped underneath. Most cells are colourless. Stains are used to add contrast. Certain stains are also used to stain specific cell structures or cell products.

Risks

  • Care must be taken when looking down the microscope if the illumination is too bright.
  • Care when using microscope stains.
  • Care when handling coverslips, microscope slides and mounted needles.