160 likes | 459 Views
Introduction to the Microscope. Nosepiece. Types Care Parts Using. Types of Microscopes. First microscopes were simple scopes One magnifying lens (i.e. one magnifying glass) Compound Microscopes Two magnifying lenses & a source of light Dissection Microscopes
E N D
Introduction to the Microscope Nosepiece Types Care Parts Using
Types of Microscopes • First microscopes were simple scopes • One magnifying lens (i.e. one magnifying glass) • Compound Microscopes • Two magnifying lenses & a source of light • Dissection Microscopes • Low magnification (cannot see cells) • Used for dissection to get a better look at the larger specimen • Scanning electron microscope (SEM) • Extremely detailed 3D views of the surface of the specimen (think of “S” for surface) • Specimens are coated with metal • Transmission electron microscope (TEM) • Electrons pass through the specimen - can view internal structure (think of “T” for through) • Specimen must be sliced into an extremely thin section - 20-100 nm and stained with metals
SEM images Bacteria Termite Blood cell Ballpoint pen
TEM images Mitochondrion Bacterium Rough ER Chloroplast
Microscope Care • Always carry with 2 hands • Never allow cords to hang over the counter • Do not force knobs • Always use the fine focus if on any power higher than scanning (4X) • Loosely wrap the cord around the scope for storage • Never place on top of the vent in front of your station!
Microscope Parts Ocular Lens- Eyepiece RevolvingNosepiece Arm ObjectiveLens Stage Stage Clips Coarse Adjustment Focus Diaphragm Fine Adjustment Focus Light Source Base
Parts of the Microscope Slide Coverslip Slide
Using the Microscope • Turn the microscope on • Lower stage • Click Nosepiece to the shortest setting (4X) • Place the Slide on the Microscope • Use Stage Clips • Look into the Eyepiece • Use the Coarse Focus to slowly bring specimen into focus • Bring specimen into focus using Fine Focus knob • Adjust diaphragm if necessary
Using High Power • Follow steps to focus using low power • Carefully turn the nosepiece to the next longest objective • Do NOTuse the Coarse Focusing Knob • Use the Fine Focus Knob to bring the specimen into focus
When Finished Observing • Bring stage all the way down • Turn nosepiece so that smallest objective is directly over the slide • Carefully remove the slide!
Microscope Terms • Magnification • Resolution • Field of View • Depth of Focus • Image Inversion
Magnification • Making an image appear larger than its actual size • For example: magnification value of 100X means an image appears 100 times larger than its actual size • Total Magnification = objective mag. x ocular mag. • Example: 40X mag. (objective) times 10X mag. (ocular) = total of 400X mag.
Resolution • The ability of a microscope to show the details of an object, ability to distinguish between 2 lines • The higher the resolution the clearer the image • Both high magnification and good resolution are needed to view the details of extremely small objects clearly.
Focusing on an Object • Remember: Locate and Focus on your object with the scanning (smallest) objective lens first • This provides: • Greater Depth of Focus – depth of 3D objects (layers) • Greater Field of View – how much of the image you can see