Microscopy

• You will use an optical microscope. The centre of the microscope has a stage which is a flat surface on which you can place the slide. The stage has clips to hold the slide in place. Below the stage there is a lamp which produces a beam of light through the microscope slide. Some optical microscopes have a mirror and it is used to reflect light up through the microscope slide
• Above the stage there are objective lenses and there are three different lenses. These usually have a magnification of 4x, 10x or 40x. At the top of the microscope, there is an eyepiece and that's where you can look through it
• First, place the slide onto the stage and put the clips on the slide to hold in place . Then select the lowest power objective lens. This would be 4x. Position the objective lens so that it is almost touching the slide. To do this, slowly turn the coarse focussing dial. When this is almost touching the lens, stop turning it. Look through the eyepiece. Slowly turn the coarse focussing dial so that this increases the distance between the objective lens and the slide and do this until the cells come into focus.
• Secondly, then use the fine focusing dial to bring the image into focus. To calculate the magnification, multiply the magnification of the eyepiece lens by the magnification of the objective lens