BACTERIOLOGY / LAB / WEEK 1: LABORATORY EQUIPMENTS

Equipment for Sterilization and Disinfection

• Autoclave

• Hot Air Oven

• Bunsen Burner

• UV Sterilizer

• 70% Alcohol and Bleach

Autoclave

• Sterilizes by using steam under pressure to kill all microorganisms, including spores

Autoclave Temperature and Parameter / Normal /

• 121*C at 15 Psi

• 15-20 Minutes

Autoclave Temperature and Parameter / Heavily Contaminated /

• 132*C at 15 Psi

• 30-60 Minutes

Hot Air Oven

• Sterilizes glassware and instruments using dry heat.

Hot Air Oven Temperature and Parameter:

• Temperature: 160-180*C

• Time: 1-2 Hours

Bunsen Burner = ?

Alcohol Lamp

Bunsen Burner

• Produces an open flame for sterilizing tools like inoculating loops and creating aseptic zones

Bunsen Burner Temperature:

• Temperature: 1300-1600*C

UV Sterilizer

• Disinfect workspaces and air in laminar flow hoods

UV Sterilizer Wavelength:

• 254 nm (UV-c radiation)

UV Sterilizer Time:

• 15-30 Minutes

70% Alcohol and Bleach

• Used for surface disinfection and tool sterilization

• _______ is effective against most bacteria but not spores

__% Sodium Hypochlorite and Ratio

• 10% in 10:1 Ratio

Cultivation and Growth of Microorganisms

• Incubator

• Anaerobic Jar

Incubator

• Maintains a controlled temperature to support microbial growth

Incubator Temperature Range / Pathogenic Bacteria /

• Temperature: 35-37*C

Incubator Temperature Range / Thermophilic Bacteria /

• Temperature: 50-60*C

Anaerobic Jar

• Cultivates anaerobic bacteria by creating an oxygen-free environment.

• Mechanism: Gas packs release hydrogen, which reacts with oxygen to form water.

Media Preparation Equipments

• Petri Dish

• Agar Base Powder

• Test Tube and Bottles

• Media Bottle and Flasks

• Analytical Balance

• Hot Plate (W/ Magnetic Stirrer)

• Distilled Water

• Graduated Cylinder

Petri Dish

• Provides a platform for bacterial growth on solid media like nutrient agar

Agar Base Powder

• Used for preparation of agar medium. May vary in ingredients

Test Tube and Bottles

• Provides a platform for bacterial growth on solid media, semi-solid media, and liquid media.

• May also be used for specimen processing.

Media Tubes and Flasks

• Stores and holds culture media during preparation and sterilization.

• Also used for cooking agar!

Borosilicate Glass Bottles

• Autoclavable and resistant to high temperatures and pressure

Analytical Balance

• Accurately measures powdered media and other chemicals for media preparation

Analytical Balance Precision:

• 0.1 mg

Hot plate and Magnetic Stirrer

• Mixes and dissolves powdered media or chemicals in water while heating

Distilled Water

• Medium used to dissolve and dilute agar and nutrients.

Graduated Cylinder

• Use to measure liquid at exact volume

Aseptic Technique and Contamination Prevention

• Biosafety Cabinet

• Inoculating Loop and Needle

• PPE

Biosafety Cabinet

• Provides containment and prevents exposure to infectious agents.

Biosafety Cabinet Standards

• HEPA-Filtered Air

• Negative Airflow

Inoculating Loops and Needle

• Use for streaking and transfer of bacteria aseptically

  > (by heating the inoculating loop before and after use)

Sterile Gloves, Gown, and Mask / PPE

• Minimizes Contamination during procedures and protects the scientists.

Observation and Identification of Microorganisms

• Microscope

• Stains

• Glass slides

Microscope

• A microscope is a scientific instrument that magnifies objects, allowing us to see details that are not visible to the naked eye.

Stains

• In microbiology, can be defined as a technique which is used to enhance and contrast a biological specimen at the microscopic level.

Glass Slides

• used for smear preparation

Sample Processing and Preparation

• Centrifuge

• Homogenizer

• Spectrophotometer

• Colony Counter

• Hemocytometer

Centrifuge

• Separate cells or particles from liquids.

• It also concentrates specimens like urine and liquid stool

Homogenizer

• Breaks down solid samples into uniform suspensions

Spectrophotometer

• : Measures optical density (OD) of bacterial cultures to assess growth.

Colony Counter

• used for counting bacterial colonies

Hemocytometer

• Manually counts bacterial or cell numbers in a liquid suspension.

Storage and Preservation

• Refrigerator

• Freezer

• Cryovials and Liquid Nitrogen

Refrigerator

• Preserve media, short-term cultures, and reagents.

• Temperature: 2–8°C.

Freezer

• Stores long-term bacterial stocks and sensitive reagents.

• Temperature: -20°C or -80°C.

Cryovials and Liquid Nitrogen

• Stores bacterial strains at ultra-low temperatures for extended periods.

• Temperature: -196°C in liquid nitrogen