Transcript ppt

Compound light microscope
A Compound Light Microscope
 Allows us to view specimens that are
too small to be seen with the naked
eye
 The specimen must be thin enough for
light to pass through
How the microscope works
1. Light from the source passes through the
diaphragm, the stage, and then through
the specimen
2. The light passes through the objective lens
3. The enlarged image (picture) is produced
4. The image is then magnified again by the
ocular or eye piece lens
5. The final image you see is enlarged (made
bigger), upside down and backwards
The letter P through a microscope
Using the Microscope
TO BEGIN:
 Always carry the microscope by the arm and support
the base
 Turn on light
 The specimen slide should have a cover slip.
 Place it on the stage and secure with the stage clips
 Start on LOW POWER with the stage in the lowest
position
 Use the coarse adjustment to bring the specimen into
view, use the fine adjustment to make the specimen
clear
To switch objectives:
 Once you are focused, you should center the structure
that you want to see then move the NOSEPIECE to
medium power.
 Use the coarse and fine adjustment to bring the
specimen into clear view.
 Once you have focused and centered in medium
power, use the NOSEPIECE to move to high power.
 You should only use the fine adjustment to focus at
high power
 Never use coarse adjustment on high power
NEVER-EVER-EVER-EVER-EVER-EVER…
When you’re finished with the microscope:
 Change the objective to the lowest power.
 Lower the stage all the way down using the
coarse adjustment.
 Turn off the light source, unplug the cord,
and coil the cord around the base.
 Carefully carry (grasping the arm and
supporting the base) back to the counter
near the storage cabinet.
 Follow the directions of your instructor.