Dacudao Forensic Instrumentation
A term referring to any process that removes or kills all forms of microbial organisms such as fungi, bacteria, viruses, spore forming, etc. present on a surface, contained in a fluid, or in a compound such as biological culture media.
Sterilization
Killing or removing all forms of microbial life (including endospores) in a material or an object.
Sterilization
Which of the following methods is not an example of sterilization?
Boiling water for 10 minutes
Which of the following is not a definition of sterilization?
The process of reducing the number of microorganisms to a safe level.
_____________are highly resistant, dormant forms of bacteria that allow them to survive extreme conditions. They are produced by certain bacteria, such as Clostridium and Bacillus species.
Endospores
This is a heat treatment that kills endospores of Clostridium botulinum, a causative agent of botulism found in canned food.
Commercial sterilization
True or False: Commercial sterilization kills endospores, including that of thermophiles or non-pathogens that may grow at temperatures above 45 degrees Celsius.
False
This is the most common method of sterilization for materials not damaged by heat.
Autoclave
Which of the following is not a characteristic of an autoclave?
It operates at a temperature of around 100°C.
Geobcillus stearothermophilus: Autoclave
_____________________________: Hot air sterilization
Bacillus subtilis var. niger
True or False: Dry heat or hot air sterilization requires at least 3 hours at 170 degrees Celsius for sterilization.
False
If autoclave uses steam under pressure as a mechanism of sterilization, how does dry heat kill microbial organisms?
Protein oxidation
______________ is used to sterilize inoculating loops and needles.
Direct flaming
This is classified under dry heat, wherein organisms are burned and physically destroyed.
Incineration
This type of dry flaming is used to sterilize disposable items such as needles, inoculating wires, glassware, etc., and other biological waste.
Incineration
This refers to the reduction of the number of pathogenic microorganisms to the point where they no longer cause diseases.
Disinfection
Which of the following does not describe a disinfectant?
Disinfectants kill all forms of microbial organisms.
This refers to the use of chemical agent on food-handling equipment to meet public health standards and minimize chances of disease transmission.
Sanitization
This refers to an infectious agent, or part thereof, presenting a real or potential risk to the well-being of man, animals, and/or plants, directly through infection or indirectly through disruption of the environment.
Biohazard
This is a crucial laboratory device used to cultivate and maintain microbiological or cell cultures by providing optimal temperature and environmental conditions.
Incubator
This type of incubator maintains temperature within a specified range, often used for bacterial or fungal cultures.
Standard Incubators
CO2 incubators are used for ________________ cultures by regulating the CO2 levels to maintain an ideal pH environment, essential for mammalian cell growth.
cell and tissue
These incubators can achieve both high and low temperatures suitable for studies requiring temperatures below ambient room temperature.
Refrigerated incubators
This incubator agitates cultures contnuously, ideal for bacterial cultures that require oxygenation.
Shaking incubators
This incubator is designed to create an oxygen-free environment and are used to culture anaerobic microorganisms that cannot survive in the presence of oxygen.
Anaerobic incubators
A ___________________is a variety of containment devices equipped with HEPA filters designed to provide personnel or both personnel and product protection from biohazard materials.
Biological safety cabinet/biosafety cabinet (BSC)
True or False: BSC protects through sterilization by heat or UV and BC protects through passage of air into a HEPA filter that removes particles larger than 0.3mm
True
What BSC Class is described in the following:
i.) Ventilated cabinet for personnel and environmental protection.
ii.) Do not offer product protection from contamination.
iii.) Has unrecirculated airflow away from the operator.
iv.) Similar airflow pattern to a fumehood but also have a HEPA filter at the exhaust outlet.
v.) Safe for use with agents requiring Biosafetly Level 1, 2, or 3 containment.
Class I
Which of the following is not true about a Class I biological safety cabinet?
It has a recirculated airflow that moves away from the operator.
This BSC is totally enclosed and ventilated with leak-tight construction and attached rubber gloves for performing operations in the cabined; also known as "glove boxes."
Class III
What BSC Class has a transfer chamber that allows for sterilizing materials before they leave the glove box. It is maintained under negative pressure and the supply air is drown in through HEPA Filters.
Class III
In which class of BSC is exhaust air treated with either double HEPA filtration or HEPA filtration and incineration.
Class III
True or False: Class II BSC is safe to work requiring Biosafety Level 1, 2, and 3 only.
False
This BSC has HEPA-filtered downflow air composed mostly of uncontaminated recirculated inflow air and exhaust most of the contaminated downflow air through a dedicated duct that exhausts outside after passing through a HEPA filter.
Class II Type B1
True or False: Class II Type C1 is safe for work involving agents treated with minute quantities of toxic chemicals or radionuclides won't interfere with the work if recirculated in the downflow of air.
False
This class of BSC is sometimes referred to as 100% Exhaust or Total Exhaust.
Class II Type B2
This BSC has a HEPA-filtered downflow air drawn from the lab or the outside air and exhaust all inflow and downflow air to the atmosphere after filtration through a HEPA Filter without recirculation in the cabinet or return to the lab.
Class II Type B2
This BSC is suitable for work involving biological agents treated with hazardous chemicals and radionuclides required as an adjucnt to microbiology applications.
Class II Type B2
True or False: Class II Type A1 BSCs are suitable for work using bioloigcal agents without volatile toxic chemicals and volatile radionuclides, as well as sterile hazardous pharmacy compounding.
False
A ______________ BSC can operate as either a Type A cabinet when in recirculating mode or a Type B cabinet when exhausting.
Class II Type C1
This BSC features a marked work area with clearly delineated spaces for storage and a work area with dedicated direct exhaust for use with hazardous vapors or radionuclides.
Class II Type C1
True or False: Class II Type A2 BSCs may also be used with tracer quantities of radionuclides that won't interfere with the work if recirculated in the downflow air.
True
A Class II Type ____ may exhaust HEPA-filtered air back into the laboratory or may be exhausted outside using a canopy connection.
A2
It is a laboratory device that uses centrifugal force to separate components of a mixture based on their density.
Centrifuge
The centrifuge utilizes a _________________ principle due to gravitational force.
sedimentation
True or False: The rapid spinning of the centrifuge generates a force that causes denser components to move inward to the bottom of the container, while less dense components remain closer to the top.
False
What are the four purposes of a centrifuge?
Separation, Purification, Analysis, and Filtration
What part of the centrifuge holds the sample containers (e.g. tubes or bottles) and spins to create centrifugal force?
Rotor
The ____________________ allows the user to set operational parameters such as speed (RPM), time, and temperature.
Control Panel
This is the enclosed space where the rotor spins. It ensures safe operation by containing the spinning rotor and any debris from possible tube breakage.
Chamber
When a tube breaks, or there are other issues with the centrifuge while running, the ___________ keeps the __________ closed.
latch, lid
Compact centrifuge for laboratory use. This type of centrifuge is used for separation of blood components and microbiological or biochemical sample preparation.
Benchtop centrifuge
True or False: To maintain the benchtop centrifuge, it is recommended to regularly clean the rotor and chamber with a dry linen and inspect for rotor damage or imbalances. It is alsoa dvised to lubricate the rotor threads if required.
False
A ______________ centrifuge has temperature control for temperature-sensitive samples. This type is commonly used to separate proteins, nucleic acids, or organelles, as well as processing blood samples for coagulation studies.
Refrigerated
To maintain the refrigerated centrifuge, one should ensure that the _____________ is functioning efficiently. It should also be cleaned and defrosted regularly to prevent ice buildup whilst avoiding overloading to maintain ____________ balance.
cooling system, rotor
It is a small centrifuge designed for tubes with low volume (e.g., 0.5 mL-2mL).
Microcentrifuge
Karl wants to use a centrifuge to extract DNA/RNA as well as conduct his small-scale protein or enzyme studies. What type of centrifuge is best advised for these applications?
Microcentrifuge
This is a high-speed centrifuge that reaches up to 150,000 RPM used for separating lipoproteins, viruses, and ribosomes, as well as analytical studies like sedimentation analysis.
Ultracentrifuge
This is a specialized centrifuge for determining packed cell volume (PCV).
Hematocrit centrifuge
This type of centrifuge operates at higher speeds than general-purpose centrifuges reaching up to 30,000 RPM for separation of subcellular organelles and purification of viruses or nucleic acids.
High-speed Centrifuge
Which step of the procedure for using a centrifuge does one inspect the centrifuge and gather the samples?
Preparation
There are three substeps in setting up the centrifuge. What are these?
1. Open the Lid
2. Place the Tubes
3. Check Alignment
Karl powered on the centrifuge and allowed it to initialize. Then, he used the ____________ to input the desired ___________ speed or relative centrifugal force. He then input the required time.
control panel, rotational
Jayson closed the lid and ensured it is locked. He then pressed start button on the control panel and monitored the operations. In which step of using a centrifuge are these included?
Starting the centrifuge
Sunny stopped the centrifuge immediately, checked the balance, and redistributed the samples as necessary. What was the problem that opted Sunny to do these?
Unusual noise or vibration
True or False: If the rotor is not spinning, you should check power connections and esnure that the rotor is properly seated.
True
Faye Ley used the centrufuge to separate Karl's blood. She noticed that there was a thin white layer in the middle containing white blood cells and platelets. What is this layer called?
Buffy Coat
What is located in the top layer of the blood after centrifugation?
Plasma
True or False: After blood centrifugation, the bottom layer consists of 55% of the total blood, the erythrocytes or red blood cells.
False
After centrifugating urine, what do you call the clear liquid portion of urine containing dissolved solutes?
Supernatant
After centrifugating urine, what do you call the concentrated cellular elements such as epithelial cells, RBCs, WBCs, crystals, bacteria, or casts?
Sediment
After urine centrifugation, the _________ can be examined through a microscope to identify elements indicative of kidney diesease, infection, or other urinary tract issues.
sediment
After blood centrifugation, the ________ can be used for coagulation tests since it contains clotting factors.
Plasma
After CSF centrifugation, what do you call the clear fluid for chemical and microbiological analysis of glucose, protein, lactate, or culture?
Supernatant
The ____________ of the CSF after centrifugation consists of concentrated cellular components for cytological or microscopic examination.
pellet
What bodily fluid was centrifugated if the supernatant consists of clear fluid analyzed for protein, LDH, glucose, and other biochemical markers and the sediment contains cells or infectious cells.
Pleural, Pericardial, or Peritoneal Fluid (Serous Fluids)
The fluid portion of the seminal fluid after centrifugation containing enzumes and nutrients.
Supernatant
What is the pellet of seminal fluid after centrifugation?
Sperm cells and debris