Description of the Equipment used in Microbiology Laboratory
Equipment used for sterilization
Autoclave
The autoclave is an example of moist heat sterilization. The primary purpose of the autoclave is
sterilizing culture media and laboratory supplies. Saturated steam under pressure above 100℃ is
used for sterilization in autoclaves. There are many autoclaves, but the most common type is the
pressure cooker laboratory autoclave.
Picture: Autoclave.
Working Principle
• Autoclaves use steam as their sterilization agent. The basic principle of an autoclave is that
all the items within the autoclave come in direct contact with the steam for a particular
period irrespective of the nature of the material- whether it is liquid, plastic ware, or
glassware.
• The amount of time and the temperature depends on the type of material being sterilized
and the increase in temperature of the cycle allows for shorter periods.
Hot Air Oven
A hot air oven applies dry heat for sterilization. Its main application is sterilizing glassware like
pipettes, flasks, metallic instruments, and scissors. Electric current provides heat in a hot air oven.
The heat is provided uniformly due to the arrangement of heating elements. The holding time
depends on temperature.
Picture: Hot air oven.
Working Principle
A hot air oven is a type of dry heat sterilization which is performed on dry materials and on
, substances that do not melt or catch fire under high temperatures. There are two types of hot air
ovens based on the working principle . Forced air hot air oven: In this type of hot air oven, the
heated air inside the oven is distributed throughout the oven with a fan. This prevents the rising
of hot air towards the top while keeping the cold air at the bottom. This allows for the adequate
heating of materials inside the oven. Static air hot air oven: In this type of oven, the heat is
produced by coils present at the bottom of the oven with no fan. The hot air rises and doesn’t
allow the effective sterilization of the materials. The equipment inside the oven acquires heat and
passes the heat towards the center, one layer at a time which allows for effective dry heat
sterilization.
Incinerator
A clinical microbiology laboratory produces hazardous wastes that need to be destroyed
appropriately. An incinerator is the best way to discard those dangerous waste. Incinerators use
heat to eliminate solids; powder, pastes, pills, sludges, liquids, boxes, and tubes. This instrument
is the best substitute for disposal because it can destroy large amounts of waste at a time without
much manual labor.
Picture: Incinerator.
Working Principle
• The incubator is based on the principle of maintaining a proper atmosphere for the growth
of microorganisms.
• Incubators have a heating system that allows for the temperature within the incubator to be
adjusted according to the type of organism cultivated inside.
• Similarly, they are provided with adjustments for maintaining the concentration of CO2 to
balance the pH and humidity required for the growth of the organisms.
• Variation of the incubator like a shaking incubator is also available, which allows for the
continuous movement of the culture required for cell aeration and solubility studies.
Instruments for Culture and Identification
Analytical Balance
An analytical balance measures the precision in determining the mass of solid objects, liquids,
powders, and granular substances. It is an electronic device and uses the principle of magnetic
force restoration, offering readability up to 0.0001 g.
Equipment used for sterilization
Autoclave
The autoclave is an example of moist heat sterilization. The primary purpose of the autoclave is
sterilizing culture media and laboratory supplies. Saturated steam under pressure above 100℃ is
used for sterilization in autoclaves. There are many autoclaves, but the most common type is the
pressure cooker laboratory autoclave.
Picture: Autoclave.
Working Principle
• Autoclaves use steam as their sterilization agent. The basic principle of an autoclave is that
all the items within the autoclave come in direct contact with the steam for a particular
period irrespective of the nature of the material- whether it is liquid, plastic ware, or
glassware.
• The amount of time and the temperature depends on the type of material being sterilized
and the increase in temperature of the cycle allows for shorter periods.
Hot Air Oven
A hot air oven applies dry heat for sterilization. Its main application is sterilizing glassware like
pipettes, flasks, metallic instruments, and scissors. Electric current provides heat in a hot air oven.
The heat is provided uniformly due to the arrangement of heating elements. The holding time
depends on temperature.
Picture: Hot air oven.
Working Principle
A hot air oven is a type of dry heat sterilization which is performed on dry materials and on
, substances that do not melt or catch fire under high temperatures. There are two types of hot air
ovens based on the working principle . Forced air hot air oven: In this type of hot air oven, the
heated air inside the oven is distributed throughout the oven with a fan. This prevents the rising
of hot air towards the top while keeping the cold air at the bottom. This allows for the adequate
heating of materials inside the oven. Static air hot air oven: In this type of oven, the heat is
produced by coils present at the bottom of the oven with no fan. The hot air rises and doesn’t
allow the effective sterilization of the materials. The equipment inside the oven acquires heat and
passes the heat towards the center, one layer at a time which allows for effective dry heat
sterilization.
Incinerator
A clinical microbiology laboratory produces hazardous wastes that need to be destroyed
appropriately. An incinerator is the best way to discard those dangerous waste. Incinerators use
heat to eliminate solids; powder, pastes, pills, sludges, liquids, boxes, and tubes. This instrument
is the best substitute for disposal because it can destroy large amounts of waste at a time without
much manual labor.
Picture: Incinerator.
Working Principle
• The incubator is based on the principle of maintaining a proper atmosphere for the growth
of microorganisms.
• Incubators have a heating system that allows for the temperature within the incubator to be
adjusted according to the type of organism cultivated inside.
• Similarly, they are provided with adjustments for maintaining the concentration of CO2 to
balance the pH and humidity required for the growth of the organisms.
• Variation of the incubator like a shaking incubator is also available, which allows for the
continuous movement of the culture required for cell aeration and solubility studies.
Instruments for Culture and Identification
Analytical Balance
An analytical balance measures the precision in determining the mass of solid objects, liquids,
powders, and granular substances. It is an electronic device and uses the principle of magnetic
force restoration, offering readability up to 0.0001 g.
