Eyepiece: The lens the viewer looks through to see the specimen.

The eyepiece usually contains a 10X or 15X power lens.

Diopter Adjustment: Useful as a means to change focus on one eyepiece so as to correct for any difference in vision
between your two eyes.

Body tube (Head): The body tube connects the eyepiece to the objective lenses.

Arm: The arm connects the body tube to the base of the microscope.

Coarse adjustment: Brings the specimen into general focus.

Fine adjustment: Fine tunes the focus and increases the detail of the specimen.

Nosepiece: A rotating turret that houses the objective lenses. The viewer spins the nosepiece to select different objective
lenses.

Objective lenses: One of the most important parts of a compound microscope, as they are the lenses closest to the
specimen.

A standard microscope has three, four, or five objective lenses that range in power from 4X to 100X. When focusing the
microscope, be careful that the objective lens doesn’t touch the slide, as it could break the slide and destroy the specimen.

Specimen or slide: The specimen is the object being examined. Most specimens are mounted on slides, flat rectangles of
thin glass.

The specimen is placed on the glass and a cover slip is placed over the specimen. This allows the slide to be easily inserted or
removed from the microscope. It also allows the specimen to be labeled, transported, and stored without damage.

Stage: The flat platform where the slide is placed.

Stage clips: Metal clips that hold the slide in place.

Stage height adjustment (Stage Control): These knobs move the stage left and right or up and down.

Aperture: The hole in the middle of the stage that allows light from the illuminator to reach the specimen.

On/off switch: This switch on the base of the microscope turns the illuminator off and on.

Illumination: The light source for a microscope. Older microscopes used mirrors to reflect light from an external source up
through the bottom of the stage; however, most microscopes now use a low-voltage bulb.

Iris diaphragm: Adjusts the amount of light that reaches the specimen.

Condenser: Gathers and focuses light from the illuminator onto the specimen being viewed.

Base: The base supports the microscope and it’s where illuminator is located.

1. 1. Parts and Functions of aCompound Microscope

2. 2. Light Microscope• Simple – uses a single lens• Compound – uses a set of lenses or lens systems

3. 3. Simple Light Microscope

4. 4. Compound Microscope• Mechanical Parts – Used to support and adjust the parts• Magnifying Parts – Used to
enlarge the specimen• Illuminating Parts – Used to provide light

5. 5. Mechanical Parts• Base – Bottommost portion that supports the entire/lower microscope• Pillar – Part above the
base that supports the other parts• Inclination Joint – Allows for tilting of the microscope for convenience of the
user

6. 6. Inclination Joint Pillar Base

7. 7. • Arm/Neck –Curved/slanted part which is held while carrying the microscope• Stage –Platform where object to
be examined is placed• Stage Clips –Secures the specimen to the stage

8. 8. • Stage Opening• Body Tube –Attached to the arm and bears the lenses• Draw Tube –Cylindrical structure on top
of the body tube that holds the ocular lenses
9. 9. Draw Tube Body TubeArm / Neck Stage

10. 10. • Revolving/Rotating Nosepiece –Rotating disc where the objectives are attached• Dust Shield –Lies atop the
nosepiece and keeps dust from settling on the objectives

11. 11. Dust Shield Revolving Nosepiece

12. 12. • Coarse Adjustment Knob –Geared to the body tube which elevates or lowers when rotated bringing the object
into approximate focus• Fine Adjustment Knob –A smaller knob for delicate focusing bringing the object into perfect
focus

13. 13. CoarseAdjustmentKnobFineAdjustmentKnob

14. 14. • Condenser Adjustment Knob –Elevates and lowers the condenser to regulate the intensity of light• Iris
Diaphragm Lever –Lever in front of the condenser and which is moved horizontally to open/close the diaphragm

15. 15. IrisDiaphragmLever Condenser Adjustment Knob

16. 16. Illuminating Parts• Mirror – Located beneath the stage and has concave and plane surfaces to gather and direct
light in order to illuminate the object• Electric Lamp – A built-in illuminator beneath the stage that may eb used if
sunlight is not preferred or is not available

17. 17. Mirror /ElectricLamp

18. 18. • Substage – Iris Diaphragm • Regualtes the amount of light necesaary to obtain a clearer view of the object –
Condenser • A set of lenses between the mirror and the stage that concentrates light rays on the specimen.

19. 19. IrisDiaphragmCondenser

20. 20. MAGNIFYING PARTS• Ocular / Eyepiece – Another set of lens found on top of the body tube which functions to
further magnify the image produced by the objective lenses. It usually ranges from 5x to 15x.

21. 21. Ocular

22. 22. MAGNIFYING PARTS• Objectives – Metal cylinders attached below the nosepiece and contains especially ground
and polished lenses • LPO / Low Power Objective – Gives the lowest magnification, usually 10x • HPO / High Power
Objective – Gives higher magnification usually 40x or 43x • OIO / Oil Immersion Objective – Gives the highest
magnification, usually 97x or 100x, and is used wet either with cedar wood oil or synthetic oil

23. 23. Objectives

24. 24. Use of the Compound Microscope

25. 25. • Make sure all backpacks are out of the aisles before you get a microscope!• Always carry the microscope with
one hand on the Arm and one hand on the Base. Carry it close to your body.

26. 26. • Be gentle.• Setting the microscope down on the table roughly could jar lenses and other parts loose.

27. 27. • Always start and end with lowest powered objective.

28. 28. • Place the slide on the microscope stage, with the specimen directly over the center of the glass circle on the
stage (directly over the light).

29. 29. • If you wear glasses, take them off; if you see only your eyelashes, move closer.• If you see a dark line that goes
part way across the field of view, try turning the eyepiece.

30. 30. • Use only the Fine adjustment knob when using the HIGH (long) POWER OBJECTIVE.• As much as possible, keep
both eyes open to reduce eyestrain. Keep eye slightly above the eyepiece to reduce eyelash interference.

31. 31. • If, and ONLY if, you are on LOW POWER, lower the objective lens to the lowest point, then focus using first the
coarse knob, then the fine focus knob.

32. 32. • Adjust the Diaphragm as you look through the Eyepiece, and you will see that MORE detail is visible when you
allow in LESS light!• Too much light will give the specimen a washed-out appearance.

33. 33. • Once you have it on High Power remember that you only use the fine focus knob!• The High Power Objective
(40x) is very close to the slide. Use of the coarse focus knob will scratch the lens, and crack the slide.
 34. 34. MAGNIFICATION• The ratio of the original image to the “magnified” image.

35. 35. RESOLUTION• limiting distance between two points at which they are perceived as distinct from one another.

36. 36. Numerical Aperture• the amount of light that which enters the objective.• The larger the NA, the greater the
resolving power of the objective.

37. 37. Mounting• Glass Slide - thin flat piece of glass, typically 75 by 25 mm (3 by 1 inches) and about 1 mm thick, used
to hold objects for examination under a microscope.• Cover Slip

38. 38. Mounting• 1. Gather a thin slice/piece of whatever your specimen is. If your specimen is too thick, then the
coverslip will wobble on top of the sample like a see-saw:

39. 39. 2. Place ONE drop of water directly over the specimen.

40. 40. • Place the coverslip at a 45 degree angle (approximately), with one edge touching the water drop, and let go.

41. 41. Staining• A technique in microscopy that is used to enhance the image of the specimen.• To distinguish
structures in cells and tissues

42. 42. How to Stain a Slide1. Place one drop of stain on one edge ofthe coverslip, and the flat edge of a pieceof paper
towel on the other edge of thecoverslip. The paper towel will draw thewater out from under the coverslip, and
thecohesion of the water will draw the stainunder the coverslip.

43. 43. • As soon as the stain has covered the area containing the specimen you are finished. The stain does not need to
be under the entire coverslip. If the stain does not cover the area needed, get a new piece of paper towel and add
more stain until it does.

44. 44. • 3. Be sure to wipe off the excess stain with a paper towel, so you don’t end up staining the objective lenses.

45. 45. • 4. You are now ready to place the slide on the microscope stage. Be sure to follow all the instructions as to
how to use the microscope.

46. 46. • 5. When you have completed your drawings, be sure to wash and dry both the slide and the coverslip and
return them to the correct places!

Biology is the natural science that studies life and living organisms, including their physical structure, chemical processes,
molecular interactions, physiological mechanisms, development and evolution.

The word biology is derived from the greek words /bios/ meaning /life/ and /logos/ meaning /study/ and is defined as the
science of life and living organism

Microscopy is the technical field of using microscopes to view samples & objects that cannot be seen with the unaided eye
(objects that are not within the resolution range of the normal eye)

icroscope, instrument that produces enlarged images of small objects, allowing the observer an exceedingly close view of
minute structures at a scale convenient for examination and analysis. ... The most familiar type of microscope is the optical,
or light, microscope, in which glass lenses are used to form the image

The Different Types of Microscopes Exploring the Top Four and More

 The Compound Light Microscope.

 The Stereo Microscope.

 The Digital Microscope.

 The USB Computer Microscope.

 The Pocket Microscope.

 The Electron Microscope.

 The Scanning Probe Microscope (SPM)

 The Acoustic Microscope.

And the desire to learn about living things was most likely the main reason for the invention of the microscope. Today,
however, microscopes are used in many other fields. For example, geologists use microscopes to examine rocks and
minerals and materials scientists use them to study plastics and polymers.

Biology is the science concerned with the study of life. ... One popular definition is that organisms are open systems that
maintain homeostasis, are composed of cells, have a life cycle, undergo metabolism, can grow, adapt to their environment,
respond to stimuli, reproduce and evolve.

What is the simple definition of life?

The property or quality that distinguishes living organisms from dead organisms and inanimate matter, manifested in
functions such as metabolism, growth, reproduction, and response to stimuli or adaptation to the environment originating
from within the organism.