Autoclaving And Sterilization Flashcards
What is the principle of Autoclaving ?
heat under steam pressure
It is at this temperature in which all microorganisms (except for prions) and their endospores are destroyed within approximately 15 minutes
Autoclaving
In autoclaving what is recommended for media, liquids, utensils, glass pipettes (degree, psi, and mins)
121 °C, 15 psi for 15 minutes
In autoclaving what is recommended for decontaminating medical wastes (degree, psi, and mins)
132 °C, 15 psi for 30-60 minutes
the main component of a steam autoclave, it is where the materials to be sterilized are placed
Pressure chamber
the purpose of the this is to seal the chamber and maintain the sterilizing conditions within the autoclave.
Lid
it indicates the pressure inside the autoclave
Pressure Gauge
pressure within the autoclave can be controlled by lifting the whistle and releasing certain amount of vapor
Pressure releasing unit/Whistle
it is present underneath the chamber to heat the water and generate steam
Steam generator
Sterilizethematerialsinside the chamber using moist heat and pressure
Autoclave
The high pressure ensures the rapid penetration of heat into deeper parts of the material
Autoclave
The moisture causes denaturation of microbial proteins
Autoclave
Once sterilization is completed, pressure inside the chamber is released through the whistle
Autoclave
9 Steps in running an Autoclave
- Check the inside of the autoclave if there are items left from the previous cycle
- Place sufficient amount of water inside the chamber
- The materials to be sterilized are then placed inside
- The lid is closed using screws to ensure airtight condition, and the electric heater is switched on
- The water then boils and the pressure is allowed to reach the designated level
- Once the pressure is reached, the whistly blows to remove excess pressure from the chamber
- After the whistle, the autoclave is run for a holding period (15 minutes or more)
- The heater is switched off and the autoclave is allowed to cool until the pressure gauge indicates the pressure inside has lowered down
- The lid is opened and the sterilized materials are taken out of the chamber
Used in order to sterilize materials in the laboratory such as culture media, glassware and other instruments
Autoclave
Used in order to sterilize medical wastes that may contain dangerous microbes
Autoclave
Precautions in using the Autoclave
The autoclave should not be overcrowded in order to ensure that all parts of the material can be penetrated by the steam
• Wastes and clean items should be autoclaved separately
• Do not attempt to open the lid when the autoclave is running
• Avoid placing materials that might melt inside the autoclave (plastic trays, etc.)
involves the direct application of high heat in materials such as inoculating loops. This can be accomplished using an open flame (a) or an incinerator (b)
Direct flaming
How many celsius is oover heating
160 to170 degrees Celsius for 1.5 to 2 hours Aseptic
creates free radicals that causes intracellular damage
Radiation
causes mutation in the DNA; destroys vegetative cells and endospores
Ionizing radiation
Used to “pasteurize” meat products
Ionizing radiation
Utilizes gamma rays and x-rays
Ionizing radiation
damages cellular DNA
Non-ionizing radiation
Used on exposed surfaces and rooms
Non-ionizing radiation
Utilizes ultraviolet rays
Non-ionizing radiation
first widely used antiseptic and disinfectant; destroys plasma membranes and denature cell proteins
Phenol
denatures proteins and causes dissolution of lipid membranes; effective at 60-90% concentration
Alcohol
used at 1:10 dilution; 3 minutes contact time
Chlorine (hypochlorite)
