U1 LAB: LAB SAFETY AND PIPETTING TECHNIQUES Flashcards
Field involved in the examination of the origins of disease at the molecular level, primarily by studying nucleic acids
Diagnostic Molecular Biology
Hands on skills
- Accuracy and precision
- Specimen collection, handling, storage and disposal
- Specimen processing
Micropipetting is for?
accuracy and precision
Specimen processing includes:
nucleic acid, protein extraction and detection
Knowledge required on the laboratory
- Laboratory mathematics
- Laboratory safety
- Result analysis and interpretation
- QA and QC
- Social, ethical, legal issues
According to WHO, this refers to the containment principles, technologies, practices that are implemented to prevent unintentional exposure to pathogens and toxins, or their accidental release.
Biosafety
Agent of biological origin that can cause disease in humans.
Biological Hazard / Biohazard
Universal Precautions
applied to blood only
Agents are not known to cause a disease
BSL-1 (Yellow)
Agents are associated with human disease
BSL-2 (Light orange)
Agents are associated with human disease and are potentially transmitted as aerosols.
BSL-3 (Orange)
Agents of life threatening nature
BSL-4 (Red)
BSL-1 agents
- E.coli JM109, DH5a
- Saccharomyces cerevisiae
BSL-2 agents
- Human blood or body fluids
- E coli. 1057:H7
- Clostridium botulinum
- Retroviral vectors
- Human cells in cell culture
BSL-3 agents
- HIV
- H1N1 Flu
- Tuberculosis
- Rabies
- Yersinia pestis
- West Nile Virus
- SARS-Cov2
BSL-4 agents
- Ebola
- Small pox
2 laboratories in BSL-4
Suit and Cabinet Laboratory
PPE in BSL-4
- Positive pressure suits
- Double ended autoclave
BSC Class II, type A1
- 70% airflow through HEPA cabinet
- 30% back into the room
- Plenum is under positive pressure
BSC Class II, type A2
- Plenum is under negative pressure
BSC Class II, type B1
- 30-40% HEPA cabinet
- 60-70% HEPA outside
BSC Class II, Type B2
- 100% of air is exhausted outside (No air recirculation)
BSC Class II, Type C1
either Type A or Type B
This is developed by OSHA for employees who may be exposed to hazardous chemicals in workplace.
Hazard Communication Standard
These are substances that affect cellular development of a fetus or embryo.
Teratogens
These are cancer causing substances.
Carcinogens
These are chemicals with flashpoint below 37.8C
Flammable
These are chemicals with flashpoint above 37.8C
Combustible
These chemicals are injurious to the skin or eyes by direct contact or to the tissue of the respiratory and GIT if inhaled or ingested.
Corrosive
These are substances that spontaneously explode or ignite or that evolve heat or flammable or explosive gases.
Reactive
Direct electrical hazard
death, shock, burns
Indirect electrical hazard
fire, explosion
This refers to destroying all microbial life including spores.
Sterilization
This refers to destroying majority of microbial life; but not necessarily spores.
Disinfection
These are chemical disinfectants which can be safely applied to the skin or mucous membrane and are used to prevent infection by inhibiting the growth of bacteria.
Antiseptics
Physical Methods
Dry heat
- Red heat
- Flaming
- Incineration
- Hot air oven
Physical Methods
Moist heat
- Pasteurization
- Boiling
- Autoclave
Physical Methods
Uses what filter paper?
nanopore
Chemical methods
- Bleach
- Ethanol
- Hydrogen peroxide
- Ethylene oxide
- Paraformaldehyde
Holding period for Autoclave
121C at 15 pound pressure for 15 minutes
Holding period for Hot Air Oven
160C for 1 hour
T/F: Test tubes and flasks should be wrapped in paper before putting in oven.
True
These are widely used to remove unwanted microorganisms from liquids.
Membrane filters
Filters are made with what material, and what is the average pore diameter?
cellulose esters, 0.22mm
Chemical Methods
What percentage of alcohol or bleach is recommended?
70% Alcohol, 10% Bleach
This has a very high penetrative power that can be highly lethal to all cells.
Ultraviolet (UV)
UV is used for?
- Cleaning surfaces (inoculation hoods)
- Laboratory benches
- Laboratory apparatus
Three conditions for a successful aseptic technique
- Work area must be disinfected
- Transfer instruments/glasswares must be sterilized
- Work must be accomplished quickly and efficiently
This container is to be lined with clear autoclave bags and should be decontaminated inside the biosafety cabinet and/or autoclaved.
Biohazard containers
This container should used for contaminated culture tubes and glasswares that are washing and decontamination.
Decontamination bins
The shaft of a pipette is also known as a?
tip holder
The thumbwheel is also known as a?
Fine volume adjustment ring
In this displacement, air is displaced by the piston.
Air displacement
In this displacement, aspiration force remains constant, unaffected by physical properties of sample
Positive displacement
T/F: In air displacement, the volume of air displaced is equivalent to volume of liquid aspirated.
True
This is preferred when dispensing aqueous solutions, which may contain low detergents and protein concentrations.
Forward Pipetting
This is performed when dispensing viscous or foaming liquids, or very minute amt of liquid.
Reverse Pipetting
When should you pre-rinse a pipette?
- Changing a tip
- Increase a volume setting
Wiping the pipette is only necessary when?
when pipetting viscous liquids
Choice of tissue for wiping the pipette
- Resistant
- Lint free
- Inert to acids and solvents
Fluid depth penetration
only <3mm
