SkarpChapter 3 of 10
Inside the Bio Lab: Safety, Equipment, and Good Habits
Enter the biology lab with confidence by mastering safety rules, essential equipment, and the everyday practices that real researchers rely on.
Step 1 – Your First Minutes in the Bio Lab
Your Role in the Lab Ecosystem
Before touching equipment, remember: you are both a potential hazard and a potential victim. Your habits affect your safety and the reliability of experiments.
Arrival Checklist
On arrival: store bags and food away from benches, silence phones, wear closed shoes and long pants, tie back hair, and secure loose items.
Hand Hygiene and PPE
Wash hands for 20 seconds, dry with disposable towels, then put on your lab coat in the lab and fasten it. Add goggles and gloves if required for the activity.
Locate Safety Equipment
Find emergency exits, eyewash, safety shower, fire extinguisher, spill kits, first aid kit, and sharps containers before you begin any work.
Pre-Experiment Mental Check
Ask yourself: Do I know what I am working with, what to do in an accident, and where to dispose of every material? If not, pause and ask.
Step 2 – PPE: What to Wear and When
PPE Based on Risk
Modern labs choose PPE based on risk assessment, not habit. Think about what you are doing today and what could go wrong.
Lab Coats
Wear a lab coat for liquids, chemicals, stains, or cultures. Keep it in the lab and fastened. Do not wear it to non-lab areas.
Eye Protection
Use safety glasses or goggles when there is splash, aerosol, heating, or UV risk. Keep them clean and wear them over prescription glasses if needed.
Gloves
Use nitrile gloves for biological samples and hazardous chemicals. Never touch your face, phone, or door handles with gloved hands.
Extra PPE
For higher risks, you may need face shields, respirators, or heat-resistant gloves. These are used when splashes, aerosols, or high heat are involved.
Quick Check – PPE Choices
Test your understanding of when to use different PPE.
You are setting up an experiment with E. coli cultures and a dilute staining solution. You will be pipetting small volumes and briefly opening tubes. What minimum PPE set is most appropriate in a standard teaching lab?
- Gloves only
- Lab coat and gloves
- Lab coat, safety glasses, and gloves
- No PPE needed if you are careful
Show Answer
Answer: C) Lab coat, safety glasses, and gloves
Working with cultures and stains involves splash/aerosol risk and contamination risk. Standard practice is lab coat, eye protection, and gloves, even for small volumes.
Step 3 – Micropipettes: Precision in Your Hands
Micropipettes Matter
Micropipettes measure microliter volumes and are central to modern biology. Good technique is essential for accurate, reproducible data.
Know the Parts
Key parts: plunger with two stops, volume dial and display, tip ejector, and the shaft for disposable tips. Never force the volume beyond its labeled range.
Aspirating Correctly
Press to the first stop before entering the liquid, immerse the tip slightly, then slowly release the plunger to aspirate without bubbles.
Dispensing Correctly
Touch the tip to the receiving tube, press to the first stop to dispense, then to the second stop to blow out the rest. Withdraw with the plunger still down.
Protect Accuracy
Keep the pipette vertical, use the smallest suitable size, pre-wet tips when needed, and never use the second stop to aspirate.
Step 4 – Pipetting Thought Exercise
Imagine you are preparing a reaction that needs 15 µL of enzyme solution and 85 µL of buffer in a 1.5 mL tube.
- Choose the pipettes
- Which pipette would you use for 15 µL?
- Which pipette would you use for 85 µL?
- Plan the sequence
- In what order would you add the components to minimize error and contamination?
- Where would you hold the tube while pipetting (rack, in hand, etc.)?
- Spot the mistakes
- A student sets a P1000 to 15 µL and uses it anyway.
- Another student aspirates enzyme with a tip they just used for buffer.
- A third student lays a pipette with enzyme in the tip flat on the bench while they label tubes.
Write down or say out loud:
- The best pipette choice for each volume.
- A safe, logical order of steps.
- What is wrong in each student's behavior and how to fix it.
Then compare your answers with a lab partner or your instructor's key.
Hint: Think about using the most accurate pipette for each volume, keeping enzyme concentrated and cold, and avoiding cross-contamination.
Step 5 – Balances and Microscopes: Getting Reliable Measurements
Balances: Mass Matters
For accurate mass, tare with a weigh boat, add solids gently, close draft shields, and wait for a stable reading. Never weigh directly on the pan or with hot objects.
Balance Do and Do Not
Do: tare containers, keep the area still and clean. Do not: pour chemicals on the pan, lean on the bench, or bump the balance while weighing.
Microscope Setup
Start with the lowest power objective, secure the slide, and use coarse focus first. Watch from the side to avoid crashing the lens into the slide.
Magnify Safely
Once you see the specimen, move to higher power and use fine focus only. Adjust light and condenser for good contrast.
Microscope Care
Carry with two hands, clean lenses only with lens paper, and store with the lowest objective in place, stage lowered, and a dust cover on.
Step 6 – Lab Etiquette: How to Behave Like a Researcher
Why Etiquette Matters
Lab etiquette is part of safety and quality control. Many accidents and contamination events start with small bad habits.
Food and Personal Items
Never eat, drink, chew gum, or apply cosmetics in the lab. Keep personal items off benches to reduce contamination risk.
Keep Benches Tidy
Only keep what you need on the bench. Label all tubes and plates immediately with contents, your initials, and date.
Respect Shared Equipment
Follow sign-in rules, reset shared instruments if required, and let others know before you open incubators or start centrifuges.
Stay Focused
Avoid horseplay and distractions, and keep phones away from the bench. Treat the lab as a professional workspace.
Step 7 – Waste Segregation and Sharps Safety
Why Waste Segregation Matters
Labs must follow current biosafety and hazardous waste rules. Correct waste bins protect people and the environment and keep your lab compliant.
Biohazard Waste
Items contaminated with biological material go into biohazard bags or bins with the biohazard symbol, often for autoclaving before disposal.
Sharps and Broken Glass
Needles, blades, and contaminated broken glass go into rigid sharps containers. Clean broken glass goes into a dedicated glass box, never regular trash.
Chemical vs General Waste
Chemical waste like stains, acids, or solvents goes into labeled waste bottles, not the sink. Only non-contaminated items go into general trash.
Sharps Safety
Do not recap needles unless trained to do so safely. Dispose of sharps immediately and alert others if glass or sharps are dropped or broken.
Check Your Waste Disposal Choices
Decide where this item should go in a typical teaching biology lab that follows current biosafety and hazardous waste practices.
You have a plastic serological pipette tip that was used to transfer a live bacterial culture. Where should it go after use?
- General trash bin
- Sharps container
- Biohazard waste container
- Rinse it and reuse
Show Answer
Answer: C) Biohazard waste container
A plastic pipette tip that contacted live culture is contaminated biological waste. It belongs in a biohazard waste container, not general trash or sharps.
Step 8 – Cleaning Up and Leaving the Lab Safely
Why Cleanup Matters
Ending a session correctly protects the next users and maintains safety compliance. Cleanup is as important as setup.
Secure Experiments and Waste
Label all samples, store them correctly, and dispose of all waste in the proper containers before you leave.
Decontaminate and Return Gear
Disinfect benches, clean spills properly, turn off instruments, and return pipettes and reagents to their designated places.
Remove PPE Safely
Take off gloves first, then your lab coat, and remove eye protection last. Dispose of or store each item correctly.
Final Step: Handwashing
Wash your hands with soap and water after removing PPE and before exiting the lab. This is your last safety barrier.
Step 9 – Key Term Review
Use these flashcards to review essential lab safety and equipment concepts.
- Personal Protective Equipment (PPE)
- Clothing and gear (e.g., lab coat, gloves, eye protection) worn to reduce exposure to hazards after engineering and administrative controls.
- Micropipette First Stop vs Second Stop
- First stop: used to aspirate and initially dispense the set volume. Second stop: used at the end of dispensing to blow out any remaining liquid.
- Biohazard Waste
- Waste contaminated with potentially infectious biological material, such as cultures, contaminated tips, and gloves; must be collected in designated biohazard containers.
- Sharps Container
- Rigid, puncture-resistant container used for disposing of needles, blades, and contaminated broken glass, preventing injury and exposure.
- Tare (on a balance)
- To zero the balance with a container in place, so subsequent readings reflect only the mass of the material added.
- Biosafety
- Practices, procedures, and equipment used to protect people and the environment from exposure to infectious agents and biological materials.
- Decontamination
- Process of removing or neutralizing contaminants (biological or chemical), often by disinfectants, autoclaving, or appropriate cleaning procedures.
- Good Lab Etiquette
- Behavioral norms in the lab, including no food or drink, organized benches, respect for shared equipment, and clear communication to support safety and data quality.
Key Terms
- Tare
- To zero a balance with a container on it so that only the mass of the added substance is measured.
- Sharps
- Items with sharp edges or points, such as needles, blades, and broken glass, that can cut or puncture skin.
- Biosafety
- The principles, practices, and equipment used to prevent exposure to infectious agents and protect laboratory workers and the environment.
- Micropipette
- A precision instrument used to measure and transfer very small liquid volumes, typically in the microliter range.
- Lab Etiquette
- Expected behaviors and practices in the lab that support safety, organization, and respect for others and shared resources.
- Biohazard Waste
- Waste contaminated with potentially infectious biological material that requires special handling and disposal.
- Decontamination
- The process of removing or inactivating contaminants such as microorganisms or hazardous chemicals from surfaces or equipment.
- Personal Protective Equipment (PPE)
- Protective clothing and gear, such as lab coats, gloves, and eye protection, used to reduce exposure to laboratory hazards.