2. Outline
• Microbiology Definition
• Safety rules in Microbiology
• General Key Terms Used in the Microbiology Lab
• List of General Materials and Equipment Used in the Lab
• How to use a microscope
• Topics that would be covered
• Grades Distribution
3. Definition of Microbiology
• It is defined as the study of microorganisms (MO)
• It can also be defined as the biology of microscopic organisms that are too small to
be seen by the naked eye. Examples include: bacteria, viruses, and yeasts.
• MO can be found almost anywhere, like on surfaces where there would be
colonies of microorganisms.
• There are certain MO that are considered harmless to the human heath. However,
some types can lead to diseases in humans, animals, and even harm plants.
4. Definition of Microbiology (Cont’d)
• Microorganisms can also be involved in food spoilage.
• Microorganisms can cause a disease by:
• Using up the nutrients or other substances used by cells and tissues by invading them
• Damaging body cells by reproducing inside the cells
• Making body cells targets of the body’s own defenses
5. Microbiology Safety Rules
❖Not allowed to eat, drink, store food or drink, bring food or drink, or apply
cosmetics while in the lab; including water bottles.
❖Lab coat is worn before entering the lab.
❖Closed shoes are to be worn at all times.
❖Personal items are not to be placed on the floor or on countertops.
❖Hair is tied back before entering the lab.
❖Long sleeves are rolled back up the arm.
❖Disinfect the area where you would be working on before and after starting the
lab work.
6. Microbiology safety rules (Cont’d)
❖In case of spill, disinfect the area.
❖Hands are washed before and at the end of the lab session.
❖After removing the gloves, wash your hands.
❖Hands, pencils, pens, etc. are kept away and out of the mouth.
❖Never pipette by mouth!
❖Alert the instructor in case of spilling.
❖While staining or handling microbes, wear gloves.
7. General KeyTerms Used in the
Microbiology Lab
• Sepsis: Microbial Contamination
• Asepsis: Absence of significant contamination
• Aseptic Techniques: Techniques that are used to prevent microbial
contamination.
• Disinfection: Removal of pathogens
• Sterilization: Removal of all microbes present
• Sanitization: Reduction of microbial numbers to a level that is considered safe
• Bacteriostatic: Inhibit bacterial proliferation
• Bactericidal: Destruction of bacteria
8. General KeyTerms Used in the
Microbiology Lab (Cont’d)
• Antimicrobial Chemicals are expected to destroy pathogens but not to reach
sterilization
• Disinfectant: Used on objects
• Antiseptic: Used on tissues like on the skin
9. General Materials and EquipmentUsed in
Microbiology Lab
• Petri dish: a shallow cylindrical glass or plastic dish with a lid used to culture cells.
• Agar plate: petri dish that contains a growth medium (usually agar with nutrients) to
culture MO.
• Cotton swabs/Cotton buds: small wad of cotton wrapped around one or both ends of a
rod.
• Inoculation loop, or smear loop: tool used ,mainly to retrieve inoculums from a culture of
MO.
10. General Materials and EquipmentUsed in
Microbiology Lab (Cont’d)
• Incubator: used for bacterial or fungal cultures.
• Microscope: used for visualizing small structures including microbes.
• Autoclave: used for sterilization of glassware and media
• Hot air ovens: electrical devices that use dry heat to sterilize.
Autoclave Incubator
12. How to use a microscope
• Ocularlens (eyepiece): lens to view the magnified the image
• Head: the upper part that includes the eyepiece tubes.
• Nose piece: rotating piece that contains the lenses.You select the different lenses through
it.
• Diopter adjustment: control knob on the eyepiece.
• Frame (arm): Usually used to be able to carry the microscope.
• Mechanical Stage: slides are placed on it.
• Stage control: allows to move the slide when clipped on the stage
• Coarse adjustment: used to make large changes in focus,bring the specimen into general
focus.DO NOT use this when viewing on high power.
• Fine adjustment: used to bring into sharp focus.
13. How to use a microscope
• Objective lenses:
• Low power objective (scanning): first lens used (4x magnification)
• Medium power objective: second lens to use (10x magnification)
• High power objective: Highest magnification used (40x magnification). DO NOT use coarse
adjustment with this lens.
• Condenser: Gathers and focuses the light from the illuminator onto the observed
specimen.
• Illumination: Light source of the microscope.
• Brightness Adjustment: allows you to adjust the amount of light coming through the
microscope.
• Base: supports the microscope.
• Light switch: turn on or off the illuminator.
14. How to use a microscope
• The objective lenses and ocular lens are cleaned with lens paper before placing the
slide on stage and using it.
• Place a cover slip on the slide before applying the immersion oil.
• Once oil is on the slide, do not move back to 40x lens to focus as oil should never
get on this lens.
• The only lens that can have oil on it is the 100x lens also known as oil immersion
lens which can also be found on the light microscope.
