In this exercise, you will become familiar with the essential components and the preparation of a workbench for the manipulation of Biosafety Level 1 (BSL-1) microorganisms, notably non-pathogenic variants of the bacterium Escherichia coli (E. coli) and the fungus Saccharomyces cerevisiae (S. cerevisieae).
The single-celled E. coli and S. cerevisieae are part of established Molecular Biology Canon and have been scrutinized extensively as generalizable and predictive models of fundamental genetics and cellular processes. In fact, many genes and pathways implicated in serious human disease were first discovered and characterized by biomedical scientists studying S. cerevisieae.
The two species have numerous applications in biotechnology, defined as the use of living organisms, or of something derived from them, to manufacture products from natural resources. While E. coli is used extensively in genetic engineering to store and produce DNA, S. cerevisia and other Saccharomyces species have been used for millenia to manufacture biology-based products for human consumption. This includes bread, beer and wine, as well as medicine and biofuels.
Learning Objectives
At the end of the activity, you will be able to:
Abilities
Identify the items on or near your workbench and describe their purpose,
Explain the health and safety risks in your work area and how to mitigate them,
Describe commonly used aseptic procedures and their purpose,
Recall what you need to do to decontaminate your workbench before and after your experiments.
Skills
Prepare an BSL-1 workbench to reduce microorganismal cross-contamination during live-cell manipulations,
Work safely with inflammable materials and liquids near an open flame,
Clean the work area after an experiment is completed.
Before You Begin Proper aseptic technique is critical for success in molecular and cell biology. Before you go to the lab, please watch the embedded Addgene video to learn some of the key strategies of aseptic technique, including personal protective equipment, setting up a clean workspace, and maintaining sterility while working.
BSL-1 Workbench Overview
Your workbench is an area where the things your need for manipulating live BSL-1 organisms are within reach.
The boundary of your workbench is marked using yellow tape. This area should be kept sterile (aseptic) and uncluttered.
Only the items shown in the photo and listed below should be kept permanently in your work area. Others can be moved into the work area while being used while others should be kept outside the work area at all times.
Photo of a BSL-1 workbench with commonly used items
Permanent Workbench Items
The items can be kept inside the workbench area:
Bunsen burner,
Vacuum aspirator,
Vortexer,
mini-centrifuge,
pipette holder,
Biowaste and chemwaste bins.
Non-permanent Workbench Items These items can be kept inside the workbench area while in use:
boxes with pipette tips,
containers with clean tubes,
racks and holders for tubes,
petri plates and culture vesicles,
media and chemical containers,
permanent markers,
ice bucket.
Other Items You Need These items should be close to your workbench, but kept out of the sterile area to avoid clutter, cross-contamination and/or fire hazards:
Squeeze bottle with 70% ethanol,
timers,
smartphone,
labelling tape,
office stables,
razor-blades,
parafilm,
absorbant pads,
loose paper/notebooks.
Health and Safety Always be safe and avoid working alone! No experiment is important enough to risk your health or the health of others!
It is strictly prohibited to work alone with hazardous materials. Make sure to wear the appropriate protective gear when dealing with chemicals! Use examination gloves only if you work with live cells. They aren't meant to protect you!
Know the location of the nearest fire extinguisher, fire alarm, telephone, spill kit, and other items you need to maintain a safe work environment.
Never be embarrassed to ask questions or help. Your peers and your supervisors will appreciate that you care enough about health and safety to risk embarrassment (which won't happen anyway)
Always move flammable items out of the work area before turning on the Bunsen burner.
Never keep flammable materials on or above your workbench.
Make sure that your flame is a safe distance from any overhead material (the burn marks of the wooden shelfs behind the burner is evidence of past "close calls").
Turn off your flame when you leave your workbench.
Wipe off non-hazardous spills immediately and dispose used towels in chemical or biowaste (not in trash-bins).
Workbench preparation The following needs to be done before each use:
Remove all non-permanent items from the workbench.
Spray the countertop with ethanol and wipe with a towel.
Disinfect any items that you are using with ethanol and wipe dry.
If you have a phone, timer or calculator, disinfect it with ethanol and wipe dry.
Spray your gloves with ethanol and rub dry
Turn on the flame
Workbench Cleanup The following needs to be done after each use:
Turn off the flame
Remove all non-permanent items from the workbench. Disinfect items (tips and tube containers, racks, etc) with ethanol and wipe dry as you remove them.
Spray the countertop with ethanol and wipe with a towel.
If you have a phone with you, disinfect it with ethanol and wipe dry.
Empty out the biological and chemical waste bins in the corresponding containers
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