(Laboratory) Autoclaving and other Sterilization Techniques Flashcards
Principle of Autoclaving:
Moist heat under steam pressure
Preferred time and temperature when autoclaving media, liquids, utensils, glass pipettes:
121 degree Celsius, 15 pounds per square inch (psi) for 15 minutes
Preferred time and temperature when autoclaving decontaminating medical wastes:
132 degree Celsius, 15 pounds per square inch (psi) for 30-60 minutes
Identify the Part of an Autoclave:
The main component of a steam autoclave; it is where the materials to be sterilized are placed.
Pressure Chamber
Identify the Part of an Autoclave:
Seal the chamber and maintain the sterilizing conditions within the autoclave.
Lid
Identify the Part of an Autoclave:
Indicates the pressure inside the autoclave.
Pressure Gauge
Identify the Part of an Autoclave:
Pressure within the autoclave can be controlled by lifting the whistle and releasing certain amount of vapor.
Pressure Releasing Unit/Whistle
Identify the Part of an Autoclave:
Present underneath the chamber to heat the water and generate steam.
Steam Generator
Sterilize the materials inside the chamber using _____ and _____
Moist Heat
Pressure
The _____ ensures the rapid penetration of heat into deeper parts of the material.
High Pressure
The _____ causes denaturation of microbial proteins.
Moisture
Once sterilization is completed, _____ inside the chamber is released through the whistle.
Pressure
Once sterilization is completed, pressure inside the chamber is released through the _____.
Whistle
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
Uses of an Autoclave:
- Used in order to sterilize materials in the laboratory such as culture media, glassware and other instruments
- Used in order to sterilize medical wastes that may contain dangerous microbes
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.)
Types of Dry Heat Sterilization:
- Direct Flaming
- Oven Heating
A Sterilization Method that involves the direct application of high heat in materials such as inoculating loops.
Direct Flaming
Direct Flaming can be accomplished using _____ or an _____
Open Flame
Incinerator
Preferred time and temperature when using Oven Heating Sterilization Method:
160 to 170 degree Celsius for 1.5 to 2 Hours
_____ creates free radicals that causes intracellular damage
Radiation
Types of Radiation:
- Ionizing Radiation
- Non-ionizing Radiation
A Radiation type that causes mutation in the DNA; destroys vegetative cells and endospores
Ionizing Radiation
Identify what type of Radiation based on the characteristic given below:
Used to “pasteurize” meat products.
Ionizing Radiation
Identify what type of Radiation based on the characteristic given below:
Utilizes gamma rays and x-rays
Ionizing Radiation
Identify what type of Radiation based on the characteristic given below:
Used on exposed surfaces and rooms
Non-ionizing Radiation
Identify what type of Radiation based on the characteristic given below:
Utilizes ultraviolet rays
Non-ionizing Radiation
A Radiation Type that damages cellular DNA
Non-ionizing Radiation
First widely used antiseptic and disinfectant; destroys plasma membranes and denature cell proteins
Phenols
An example of a Phenol Type Disinfectant:
Lysol
Denatures proteins and causes dissolution of lipid membranes; effective at 60-90% concentration
Alcohol
Alcohol is effective at what concentration?
60-90% Concentration
Used at 1:10 dilution; 3 minutes contact time
Chlorine (Hypochlorite)
Chlorine (Hypochlorite) is used at _____ dilution.
1:10
Chlorine (Hypochlorite) contact time:
3 Minutes
Dilution Formula:
C1V1 = C2V2
Initial Concentration is substituted by _____
C1
Final Concentration is substituted by _____
C2
Initial Volume is substituted by _____
V1
Final Volume is substituted by _____
V2
In the equation C1V1 = C2V2, “C” indicates _____
Concentration
In the equation C1V1 = C2V2, “V” indicates _____
Volume
In the equation C1V1 = C2V2, “1” indicates _____
Initial
In the equation C1V1 = C2V2, “2” indicates _____
Final
