ZooLab 1 Microscopy

• The development of microscopes from a simple magnifying lens to a compound light microscope and then to the electron microscope is important to biologists/scientists that help to enlarge images which are microscopic in nature so as they can be studied.
• The compound light microscope is an instrument containing two (2) lenses to increase the magnification of objects and variety of knobs to resolve (focus) of the pictures.
• The objects must be thin, so light passes through them, and mounted on a surface, such as glass.
• The lens system of the microscope is formed by the ocular lenses (eyepieces) and the objective lenses.
• Binocular microscopes are parfocal meaning when magnification of one objective lens is in focus, then the other objectives will also be in focus at the new setting.
• The power switch on the microscope turns the lamp on and off.
• The illumination control on the microscope adjusts the brightness of the lamp.
• The illuminator on the microscope consists of a lamp bulb and one or more lenses to produce a cylindrical beam of light directed toward the base of the condenser.
• The condenser on the microscope contains a set of lenses that focus the light on the specimen.
• The focusing knob on the microscope moves the condenser up and down to adjust the focus of the light on the specimen.
• The front lens on the microscope is the glass surface closest to the specimen and should not be touched as it is easily scratched.
• The iris diaphragm on the microscope controls the aperture of the illuminating light and used to adjust contrast.
• The revolving nosepiece on the microscope holds several objective lenses that can be rotated into position to change the lens.
• The objective lenses on the microscope create a magnified image of the specimen.
• The scanning lens on the microscope is used to get an overview of the structures present in a section and to find areas for more detailed observation.
• The LPO 10x lens on the microscope is the most useful magnification to identify tissues.
• The HPO 40x lens on the microscope is used to see the details of cell and tissue organization.
• The OIO 100x lens on the microscope requires the use of immersion oil, is used primarily to see subcellular details.
• The eyepiece on the microscope forms an image that can be visualized by the eye or a camera.
• In a binocular microscope, the distance between the two tubes can be adjusted to fit the distance between the observers’ eyes.
• The focusing controls on the microscope are used to raise and lower the specimen stage to focus the image of the specimen.
• The specimen stage on the microscope holds the microscope slide.
• The slide holder on the microscope is a spring-loaded device to hold the microscope slide in place on the stage.
• The slide holder travel controls on the microscope allow the slide to be moved along two axes: longitudinal and lateral.
• Magnification is the ability to enlarge an image (what you see looking through the eyepiece).
• The total magnification for the microscope is obtained by multiplying the magnification of the eyepiece times the magnification of the objective lens.
• The eyepiece on the microscope is 10x and the three objective lenses are 4x, 10x and 20x.