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30 Cards in this Set

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What does physical control in a lab test involve?
Physical control involves the reduction in numbers or the total elimination of potentially pathogenic microorganisms from the environment.
to avoid disease infestation..
What is Disinfection?
the killing or removal of all pathogens from an object, thus rendering it safe for handling, although it is not sterilized.
definition in a lab
What is Sterilization?
The killing or removal of all living things from an object or substance.
Definition
What are the eight possible ways to physically control a lab?
Heat
High Osmotic Pressure
Centrifugation
Radiation
Mechanical Removal
Filtration
Low Temperatures
Drying
HCRMDLFH
What is an Antiseptic?
An agent that disinfects animate objects.
What is a Disinfectant?
An agent that disinfects inanimate objects.
What is a bactericide?
An agent that kills bacteria
What is a viricide?
An agent that kills viruses
What is a fungicide?
An agent that kills fungus
What is a germicide?
A general term for an agent that kills microorganisms
What is a bacteriostatic agent?
It inhibits the growth of bacteria, but does not kill them.
Example: refrigerators and freezers.
To choose an appropriate sterilizing or disinfecting agent what 4 things should you consider?
-The type of organism to be controlled
-The degree of hydration of the cells
-The substrate
-The environment(Ph, temperature,extraneous organic material)
What is pasteurization?
The destruction of pathogenic microorganisms by heating at 62.8º C for 30 minutes,
or
71.7º C for 15 seconds,
or
100º C for 0.01 seconds
What is it to Autoclave?
Moist heat of 121 C under 15 pounds of pressure for 20 minutes will sterilize. This method kills by coagulating cellular proteins and enzymes.
What is it to Fractional sterilize? (Tyndallization)
Involves heating at 50-60 C for 10 minutes for 3 consecutive days. This method will sterilize.
Boiling at 100 C for 2 hours will sterilize.
Sterilization by dry heat of ___degrees C for __ hours will kill spores, while ___ degrees C for __-__ minutes wil kill vegetative cells.
160 for 2 hours
50-70C for 5-10 minutes
What is radiation of varying wavelengths in the electromagnetic spectrum used for?
Disinfection and sterilization of heat-labile materials.
Wavelength of UV light?
250-270nm
Microwaves themselves ___(DO/DON'T) sterilize, but the heat produced by microwaves can result in sterilization.
Don't
Gamma radiation and x-rays are forms of ______ _________.
ionizing radiation
Gamma radiation and x-rays effectively sterilize many materials, but must be used cautiously because of what?
The potential danger to human cells.
What are 2 things gamma radiation and x-rays used for?
-Sterilizing plastics
-Being considered for food sterilization.
What kind of filters are used for filtration of liquids and gases?
millipore filters (.20 to .45 microns)
Filtration removes all ___ but NOT _____.
Bacteria
Viruses
normal saline percentage of isotonic solution?
85%
What does Osmotic pressure control involve?
increasing the sugar and salt concentrations to preservative level (anywhere from 15-60%)
Oxygen tension can be used for what types of organisms?
aerobic and anaerobic
Clostridium species are (anaerobic/Aerobic) sporeformers?
anaerobic
What are the three diseases of clostridium sporeformers?
botulism,
gas gangrene,
and
tetanus
What can be used to kill clostridium sporeformers?
Oxygen (aerobic conditions)