Suggested practical - Preparing light microscope slides

Aims

To prepare and stain cells for examination with a light microscope.

Method for animal cells - human cheek cells

biological samples for examination

Method for plant cells - onion epidemal cells

Onion epidermal cells

A small square or circle of thin glass called a coverslip is placed over the specimen. It prevents the slide from drying out when it's being examined. Iodine stain can be used to stain plant cells to make the internal structures more visible.

Most cells are colourless. Stains are used to add contrast. Certain stains are also used to stain specific cell structures or cell products.

The process of applying and distributing a stain next to a coverslip

With cheek cells the stain methylene blue can be used. This stains the nucleus blue.

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 and microscope slides.