Ex. 1 - Aseptic Techniques and Inoculation of Media Flashcards
There are accepted methods of carrying out activities or operations in a laboratory where pathogenic or non-pathogenic microorganisms are handled.
Good laboratory practices
This can also help in minimizing variability, and improve reliability and reproducibility of microbiological data that is obtained.
Careful oberservance
This is the basic component of most microbiological tests.
Culture media
T or F: It is important to choose the appropriate media or components in making the media based on accepted references.
True
T or F: Different media types have different media requirements (e.g., heating, additives, pH adjustment)
True
It is the universal diluent for microbiological media.
Water
Type of water is the most often used in media preparation.
Purified water (NOTE: in some cases, deionized or distilled water can be used depending on the instructions)
T or F: Consistent preparation of media DOES NOT require accurate weighing of dehydrated media or media constituents.
False - it is required
T or F: Dehydrated media should be thoroughly dissolved before dispensing and sterilization.
True
What is the general indication of overheating?
Darkening of media or Maillard-type reaction or Nonenzymatic browning
T or F: Sterilization of media can be performed even without parameters from the manufacturer or validation from the user.
False - it should be performed within the parameters provided as well as based on the validity of the user
What is the most preferred sterilization technique? What is the catch?
Autoclaving with moist heat, it cannot be used for heat-labile components as it may deteriorate and harm the quality of the media
The second appropriate sterilization technique that can be used
Sterilization by filtering or filtration
Recommended parameters when using an autoclave
121 degrees Celsius for 15 minutes at 103 kPa (15 psi)
T or F: Sterilization time will be dependent on the media volume and autoclave load.
True
T or F: Storage of media in the autoclave after the liquid cycle is completed is recommended.
False - it is not recommended as it may damage the media
How many times should re-melting of media be done?
Only once
If re-melting will be done, how should it be done?
Should be done in a heated water bath or by using free-flowing steam
In microbiological cultures, what should be done before use in quality control testing?
Confirmation of the purity of the culture and its identity
This technique is the one recommended for storage of stock cultures.
Seed-lot technique
T or F: Discard unused portion of cell suspensions to minimize the risk of viability and contamination of the stock.
True
T or F: The number of transfers of working control culture should be tracked.
True - to prevent excessive sub-culturing that increases the risk of phenotypic alteration or mutation
T or F: The laboratory layout and design should minimize cross-contamination of microbial cultures.
True
A laboratory should be divided into ____?
Two, clean or aseptic areas and live culture areas
Equipment that are difficult to sanitize (e.g., refrigerators and incubators) should be dedicated to _______ to minimize potential of inadvertent contamination.
aseptic operations and live culture operations
T or F: All microbiological samples should be taken using aseptic techniques, including nonsterile products.
True