Microbiology
Laboratory Equipment and Procedures
2:1 The Light Microscope
MICROSCOPE:
Micro –
Scope –
SIMPLE MICROSCOPE:
e.g.
COMPOUND MICROSCOPE:
LIGHT MICROSCOPE:
Parts of the Compound Microscope
1. EYEPIECE: (ocular)
2. BODY TUBE:
Chapter 2
3. OBJECTIVES:
4. NOSEPIECE:
5. ADJUSTMENTS:
6. STAGE:
7. STAGE CLIPS:
8. DIAPHRAGM: (iris)
9. MIRROR or LAMP:
10. BASE and ARM:
2:2 Magnification and Resolution
MAGNIFICATION:
TOTAL MAGNIFICATION =
e.g. eyepiece power =
TM =
TM =
TM =
objective power =
X
X
Image is enlarged
times
MAGNIFIED IMAGE:
In a compound microscope the magnified image will
appear
RESOLUTION: (resolving power)
The
microscopes is limited by the
of light
Limit of resolving power =
Wavelength of visible light =
Resolving power light microscope =
Diameter of bacteria =
WORKING DISTANCE:
2:3 Other Types of Microscopes
ELECTRON MICROSCOPE:
TRANSMISSION ELECTRON MICROSCOPE:
SCANNING ELECTRON MICROSCOPE:
Other Types of Microscopes
1. ULTRAVIOLET MICROSCOPE:
 Wavelength of UV =
 Resolving power of UV =
2. FLUORESCENCE MICROSCOPE:


3. DARK FIELD MICROSCOPE:


4. PHASE CONTRAST MICROSCOPE:
2:4 Techniques for Microscopic Study
HANGING DROP PREPARATION:
 Hanging drop preparation
STAINING BACTERIA:
SMEAR:
 Bacteria have an overall negative charge
 Basic dyes (pH above 7)
 Acidic dyes (pH below 7)
SIMPLE STAIN:
NEGATIVE STAIN:
GRAM STAIN:
 GRAM POSITIVE:
 GRAM NEGATIVE:
ACID-FAST STAIN:
2:5 Growth and Preparation of a Pure Culture
PURE CULTURE:
MEDIUM:
COLONY:
INOCULATION:
AGAR:
STREAK PLATE:
2:6 Culture Media and Sterilization
INFUSION MEDIA (aka nutrient broth or nutrient agar):
Agar may be added to nutrient broth
Other types of media (
) may be used to identify
unknown cultures, diagnose diseases, and inhibit growth of certain species.
Media and tools used in bacterial procedure must be sterile (
to insure that
Sterilization Methods
1. AUTOCLAVE:
2. FILTRATION:
3. HOT AIR STERILIZATION:
2:7 Microbial Cultivation Requirements
Conditions Needed for Microbial Growth
1. Food:
2. Water
3. Proper temperature:
4. Proper pH:
5. Darkness:
)
Classifying Bacteria by Oxygen Requirement
1. STRICT AEROBES:
2. STRICT/OBLIGATE ANAEROBES:
3. MICROAEROPHILIC:
4. FACULTATIVE AEROBE/ANAEROBE:
 Aerobically
 Anaerobically
5. AEROTOLERANT: