Basic Lab Skills Training
TLDRThis instructional video guides new lab students through essential equipment usage, including pipettes for precise liquid transfers, balance calibration for accurate weighing, and centrifuge operation for density separation. It covers pipette tips, plunger settings, and troubleshooting inaccuracies. The video also explains how to use a pipette aid for larger volumes, maintain a pH meter, and prepare buffers. Safety tips for fume hoods and the importance of ultrapure water for experiments are highlighted, along with stir plates and hot plates for solution preparation, emphasizing safety and accuracy in lab practices.
Takeaways
- 🔬 Pipettes are essential for accurately transferring liquid volumes in the lab and come in various sizes with different volume ranges indicated on the plunger.
- 🔄 To adjust the volume setting on a pipette, rotate the black knob near the top, noting the color-coded digits for different units of volume.
- 🌡️ Pipettes require unique tips and a two-stop plunger system for drawing up and ejecting liquids, ensuring complete transfer.
- 🗑️ After use, pipette tips should be ejected into a Sharps box using the ejector button or manually if the button is not available.
- 📐 Inaccuracy in pipettes can be tested using an analytical balance, and if found inaccurate, they require calibration and should be reported to a supervisor.
- 💧 For transferring larger volumes over 1 ml, a pipette aid is used, which operates with larger tips and an air filter to prevent contamination.
- ⚖️ Balances are crucial for weighing chemicals, with analytical balances being precise for small masses and crude balances for larger ones.
- 🧪 Weighing small masses should be done on weighing paper to minimize cling, and any excess chemical can be returned to the original bottle if the spatula is clean.
- 🔄 To maintain balance accuracy, standardized weights should be used for testing, and any significant inaccuracies should prompt calibration or notification of a supervisor.
- 🌀 Centrifuges are used for separating particles of different densities and require properly balanced samples to prevent damage or injury.
- 🏗️ When using centrifuges, especially with large containers, fill them only to 80% capacity to prevent spills during high-speed spinning.
- 📊 pH meters need to be calibrated using standard solutions and the electrode must be stored in electrode storage solution to prevent damage.
- 🛠️ Buffers are essential for maintaining pH stability in solutions and should be chosen based on their pH range and chemical reactivity to suit the experiment.
- 🌫️ Fume hoods are used for working with hazardous chemicals and require proper sash height, airflow, and cleanliness to function safely.
- 💧 Ultrapure water systems provide water free of contaminants, essential for buffer preparation, and should be checked for resistivity to ensure purity.
- 🔥 Stir plates and hot plates are used for mixing and heating solutions, respectively, with caution advised to prevent accidents or equipment damage.
Q & A
What is the main purpose of the video?
-The main purpose of the video is to train new students on how to use basic laboratory equipment such as pipettes, balances, centrifuges, pH meters, and fume hoods, as well as how to handle ultrapure water systems.
What are pipettes used for in a lab?
-Pipettes are used to accurately transfer liquid volumes in a lab, with sizes ranging from 0.2 microliters to 1000 microliters.
How do you change the volume setting on a pipet?
-To change the volume setting on a pipet, you rotate the black knob near the top of the pipet. The volume range is indicated on the plunger, and for some pipets, one of the digits is shown in red to indicate milliliters or nanoliters.
Why is it important to ensure that the tips of pipettes fit snugly?
-It is important to ensure that the tips fit snugly to prevent leakage and ensure accurate liquid transfer, as loose or ill-fitting tips can lead to improper functioning and inaccurate measurements.
What is the two-stop plunger system on pipettes used for?
-The two-stop plunger system on pipettes is used to transfer liquids: the first stop is for drawing up the liquid, and the second stop is for completely ejecting the liquid from the tip.
How can you test the accuracy of a pipet?
-You can test the accuracy of a pipet using an analytical balance by setting the pipet to a known volume, transferring the liquid to a weigh boat, and comparing the measured weight to the expected weight based on the density of the liquid.
What should you do if a pipet is found to be inaccurate?
-If a pipet is found to be inaccurate, you should stop using it for experiments and immediately inform your supervisor so that the pipet can be calibrated.
How do you use a pipet aid for transferring volumes larger than 1 ml?
-To use a pipet aid for volumes larger than 1 ml, you insert the large tip into the pipet aid, submerge the tip into the liquid, use the top button to draw up the liquid, and the bottom button to eject it. If the pipet aid stops working after drawing up too much liquid, you may need to disassemble and clean the air filter.
What are the two types of balances commonly found in labs and when should they be used?
-The two types of balances are crude balances for large masses and analytical balances for very small masses. Crude balances should be used for masses larger than 1 gram, while analytical balances should be used for masses smaller than a gram.
How can you ensure the accuracy of an analytical balance?
-To ensure the accuracy of an analytical balance, you can test it with standardized weights at the upper and lower bounds of the balance's range. If the readings are significantly off, the balance may need to be calibrated following the manufacturer's instructions or with guidance from a supervisor.
What is the correct procedure for using a centrifuge?
-When using a centrifuge, ensure that samples are properly balanced using an analytical balance, placed opposite each other on the rotor, and covered with lids. Set the appropriate gForce or RPM, time, and watch the centrifuge reach maximum speed to check for imbalances. After the run, wait for the rotor to stop and check for proper sedimentation before cleaning up any spills.
Why is it important to store the pH meter electrode in storage solution?
-The electrode of a pH meter must be stored in storage solution to prevent damage and maintain proper functionality. If the storage solution runs dry, the electrode may break, and the pH meter may stop working accurately.
How do you calibrate a pH meter?
-To calibrate a pH meter, use pH standard solutions of 4, 7, and 10, depending on the pH range of the solution you are measuring. Rinse the electrode, submerge it in the standard solution, and follow the manufacturer's instructions for calibration. After calibration, ensure the reading stabilizes before adjusting the pH with hydrochloric acid or sodium hydroxide.
What are some considerations when working with buffers?
-When working with buffers, consider their pH range and chemical reactivity. Ensure the buffer is effective within the desired pH range and does not interfere with the chemical reaction, such as by binding metal ions or generating free radicals.
What are the safety precautions when working in a fume hood?
-When working in a fume hood, ensure proper airflow, work at least 6 inches deep, keep the hood clean and unobstructed, and avoid raising the sash too high. If there are any issues with the hood's function, inform your supervisor immediately.
How should you collect and store ultrapure water?
-To collect ultrapure water, place the dispensing hose in your bottle and pull the trigger. Check the resistivity on the system readout to ensure the water is ultrapure (18.2 megaohms per centimeter). Avoid leaving bottles unattended on the bench to prevent overflow and potential lab flooding.
What are the safety considerations when using a hot plate?
-When using a hot plate, do not heat water above its boiling point without intention, avoid heating volatile solvents without proper ventilation, and never leave a hot plate unattended at high temperatures for extended periods to prevent fire hazards.
Outlines
🧪 Lab Equipment Basics: Pipettes and Pipette Aids
This paragraph introduces the fundamental lab equipment for new students, focusing on pipettes and pipette aids. It explains the different sizes of pipettes, which range from 0.2 microliters to 1,000 microliters, and how to adjust the volume settings. The importance of using the correct tips for each pipette is emphasized, as is the two-stop plunger system for liquid transfer. The video also demonstrates how to test pipette accuracy using an analytical balance and the steps to take if a pipette requires calibration. Additionally, the use of pipette aids for larger volumes and the process of unclogging them with air filters are covered.
🔍 Accurate Weighing and Centrifuge Safety
The second paragraph delves into the use of balances for weighing chemicals in a lab setting, distinguishing between crude and analytical balances based on the mass being measured. It outlines the proper procedure for weighing with a weighing boat and weighing paper, and the importance of cleaning up spills immediately. The paragraph also covers the testing of balance accuracy with standardized weights and the calibration process if necessary. Furthermore, it discusses the use of centrifuges, emphasizing the need for balanced samples, proper sealing, and safety precautions to prevent damage or injury.
📊 pH Meter Calibration and Buffer Considerations
This section covers the correct use and calibration of pH meters, highlighting the necessity of storing the electrode in the appropriate storage solution and the steps for calibration using standard pH solutions. It also touches on the adjustment of pH levels in solutions using hydrochloric acid or sodium hydroxide. Additionally, the paragraph provides insights into the function of buffers in maintaining pH stability and the factors to consider when selecting a buffer, such as pH range and chemical reactivity.
🌪 Fume Hood Protocols and Ultrapure Water Usage
The final paragraph addresses safety protocols when working in a fume hood, including checking air flow, maintaining a safe distance from the sash, and keeping the hood clean and unobstructed. It also explains the importance of using ultrapure water in experiments and the process of collecting it from a dispensing system, ensuring its purity by checking resistivity levels. Moreover, the paragraph provides guidance on the use of stir plates and hot plates, with a focus on safety precautions when heating liquids.
Mindmap
Keywords
💡Pipet
💡Volume Range
💡Plunger
💡Two-Stop Plunger System
💡Centrifuge
💡Balance
💡pH Meter
💡Buffer
💡Fume Hood
💡Ultrapure Water
💡Stir Plate
Highlights
Training new students on basic lab equipment usage.
Introduction to pipettes and their various sizes for different liquid volume transfers.
Explanation of how to read the volume range on pipette plungers.
Demonstration of changing volume settings on pipettes.
Importance of using the correct pipette tips for accurate liquid transfer.
Description of the two-stop plunger system for pipettes.
Technique for transferring a sample using pipettes.
Proper disposal of used pipette tips in a Sharps box.
Method to test pipette accuracy using an analytical balance.
Procedure for calibrating a pipette if it's found to be inaccurate.
Introduction to pipet aids for transferring larger volumes of liquid.
How to handle a pipet aid malfunction and the importance of air filters.
Usage of balances for weighing chemicals in a lab.
Difference between crude and analytical balances and their appropriate uses.
Technique for cleaning up chemical spills in the lab.
Centrifuge usage and safety precautions.
Proper sample balancing for centrifuge operation.
pH meter calibration and usage.
Importance of electrode storage solution for pH meter maintenance.
Buffer solutions and their role in maintaining pH levels.
Fume hood safety and proper usage guidelines.
Ultrapure water system usage for contaminant-free water in experiments.
Stir plate usage for mixing solutions in lab experiments.
Safety measures when heating liquids on a hot plate.
Transcripts
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