Anat 1 Micro Lab 1
Dr. Fickbohm
1
Introduction to the Microscope
NOTE: Our microscopes have a functional range of magnification from 40 times to 400 times.
Since the body’s cells are generally translucent and colorless, staining processes are used to make particular structures
more visible. Not all of the slides have been stained in the same way, so structures must be analyzed by their
distinctive shape and texture, and by their relationship to adjacent structures, not by color.
Some basic guidelines for using the microscope:
1. When carrying a microscope,use both hands, one supporting the base, the other gripping the arm.
2. When using the scope, do so gently. Always control the spring clip to avoid cracking the slide.
3. Before plugging in the scope, check that its electrical cord is not frayed or otherwise damaged. Contact the
instructor if you find any damage or have any questions.
4. Use only lens paper to wipe the lens.
5. Before putting the scope away, return the low power objective to the working position. Do not wrap the
electrical cord around the microscope -- fold the cord over itself and enclose it with the strap or rubber band.
Before setting up a slide, become familiar with the parts of the microscope using the diagram. Use the list below to
review the parts of the microscope.
1. Ocular or Eyepiece: microscopes may be monocular or biocular (having one or two oculars, respectively).
The ocular is a lens responsible for a portion of the magnification (the other magnifying lens is the objective).
Oculars are typically 10x or 20x (magnifying 10 or 20 times, respectively).
2. Monocular Body Tube: transmits light rays from the light source, through slide, to the ocular
3. Nosepiece: rotatable holder for objectives
4. Objective: one of two magnifying lenses (the other is the ocular). Objectives range from 4x to 400x or greater.
5. Spring Clip of Mechanical Stage: the clip holds the slide on the stage, which is designed to support the slide.
6. Mechanical Stage: the flat surface for placement of the slide which as adjustable brackets and clip for
securing slide.
7. Diaphragm Lever: controls the iris diaphragm that can widen or narrow to increase or decrease light on the
specimen
8. In-stage Condenser: optical lens that can concentrate or diffuse light throught the specimen by virture of its
position, as controlled by the condenser control knob. The highest position, nearest the specimen concentrates
the light the most at the center of the field. Lowering the condense diffuses the light, i.e. the light is “spread
out”, which is useful for faintly stained or unstained specimens to avoid flooding the specimen with light.
9. In-base Illuminator: provides light source; usually the intensity of the light can be adjusted by a numbered
Anat 1 Micro Lab 1
Dr. Fickbohm
2
knob placed either on the base or the arm of the scope.
10. Base: supports the microscope
11. Course Focus Control Knob: adjusts the focus by creating large changes in focus, by raising or lowering
either the nosepiece or the mechanical stage.
12. Fine Focus Control Knob: adjusts the focus by creating smallchanges in focus, by raising or lowering either
the nosepiece or the mechanical stage.
13. Condenser Control Knob: adjusts the position of the condenser (see #8)
14. Arm: supports the body tube and upper optical system of the microscope
15. Mechanical Stage Adjustment Knobs: adjust the position of the slide held on the mechanical stage.
Microscope Lab 1: Viewing some slides of stained cells/tissues
Before setting up a slide to view, go through the list of microscope parts provided above. Gently turn the knobs and
move the levers and see what happens. Note that...
There are three or four objectives (usually 4x, 10x, 40x, and possibly, 100x). The magnification is equal to the power
of the objective times the power of the ocular or eyepiece. Most of the work in this class will be done with the 10x and
40x objectives.
Keep in mind that the higher the magnification, the greater the amount of light is needed. Also, the darker the slide, the
greater the amount of light is needed. Once you have a slide set up, see if you can enhance the resolution (clarity) by
adjusting the level (height) of the condenser.
After you have become familiar with the microscope’s parts and their functions, chose a slide from the slide box
and complete the following procedures.
1. Examine the slide before you place it on the stage. Note where the specimen is under the coverslip. Place the slide
onto the mechanical stage, gently releasing the clip to hold the slide in place. Be careful to avoid cracking the corner of
the slide.
2. Looking on from the side, NOT through the ocular, position the specimen over the center of the opening in the
mechanical stage.
3. Put the low power objective in place (always scan the slide first with a low power objective). Make sure the
objective is in a “locked” position on the nosepiece. You can feel it lock into position as the nosepiece rotates.
4. Again, looking on from the side, rotate the course focus until the objective and slide are as far apart as possible and
the course focus control knob can no longer be turned. View the slide through the ocular and gently roll the course
focus control knob back until focus is reached. Note: while looking through the ocular, keep both eyes open — this
will reduce eye strain.
5. Locate a portion of the specimen that you would like to view more closely; using the mechanical stage knobs that
control the position of the slide on the stage, move the slide so that the portion you would like to view is in the center
of the field.
6. Once you have focused with the lower objective, rotate the nosepiece to move the next higher objective into place.
Note that the higher power objectives are longer and will be closer to the slide. Always take care when rotating the
nosepiece so that the slide is not damaged.
Anat 1 Micro Lab 1
Dr. Fickbohm
3
LAB ASSIGNMENT #1:
Complete the following in class and turn in to the instructor by the end of class.
(1) View the Mitosis slide at 40, 100 and 400x. Locate examples of ANAPHASE and METAPHASE. Draw 3
adjacent cells for both of the examples listed, as seen at 400X. One of the three cells should be in
anaphase or metaphase, depending on what you are illustrating. Include as much detail as possible. (You
may use your textbook as a reference.)
(2) View a slide of the thyroid gland at 40, 100 and 400x. Draw a group of 10 cells that are part of a thyroid
follicle, as seen at 400x. Label the nucleus, cell membrane and cytoplasm of one of the cells. (You may use
your textbook as a reference.)