Overview
This lecture introduces how to properly use a micropipette, including identifying types, setting volumes, using tips, and transferring liquids safely.
Types and Parts of Micropipettes
- Micropipettes are used to measure and transfer small volumes of liquid.
- Common types: P1000 (max 1000 µL), P200 (200 µL), and P20 (20 µL); labels indicate volume limits.
- Pipettes display allowable volume ranges and are color-coded for easy identification.
- Main parts: plunger, volume dial, shaft, and tip ejector button.
Volume Setting and Safety
- Always set the volume within the displayed range; never exceed maximum or drop below minimum.
- Turn the volume dial only when unlocked and lock in place after setting.
- Setting above or below range can damage the pipette's internal spring.
- Safe reset position for all pipettes: 020 (top to bottom: 0-2-0).
Using Tips and Pipetting Technique
- Match pipette tips by color: blue for P1000, green for P200, red for P20.
- Attach the tip firmly without forcing or breaking it.
- Always keep pipette pointed downward, especially when it contains liquid.
Transferring Liquids
- Press plunger to the first stop before inserting into liquid; release plunger slowly to draw up liquid.
- Check for air bubbles in the tip after drawing up.
- To dispense, press the plunger to the second stop and remove pipette from liquid while plunger is still depressed.
- Always eject the tip into a proper waste container after use.
Accuracy Check
- To verify correct volume, weigh the dispensed water; 1 mL water ≈ 1 g.
Key Terms & Definitions
- Micropipette — Tool for measuring and transferring precise, small liquid volumes.
- Plunger — Button at the top used to aspirate and dispense liquid.
- First position/stop — Initial plunger resistance for drawing liquid.
- Second position/stop — Deeper resistance for dispensing all liquid.
- Tip ejector — Button to remove used tip safely.
- Shaft — Lower part where the tip attaches.
Action Items / Next Steps
- Practice setting volumes and pipetting water using each type of micropipette.
- Remember to use the correct tips and keep within the safe volume range.
- Ask for help from teaching staff if uncertain about the correct pipette settings.