Micropipetting Lecture Notes

Introduction

• Importance of understanding micropipette operations in labs.
• Essential for biochemistry and biological labs.

Types of Micropipettes

1. P200 Micropipette

   • "P" stands for pipette and "200" for its max volume of 200 microliters.
   • Yellow tip indicates compatibility with yellow micropipette.

2. P1000 Micropipette

   • Max volume of 1000 microliters (1 mL).
   • Blue tip for blue micropipette.
   • Volume can be adjusted; no decimal shown on dial.

3. Multi-Channel Micropipettes

   • Multiple channels (8 or 12) for simultaneous liquid handling.
   • Used less frequently; necessary for enzyme kinetics lab.

Operation of Micropipettes

• Ergonomic handling: wrap fingers, operate piston with thumb.
• Volume adjustment using the dial:
  • P200: Precise to the tenth decimal place.
  • P1000: No decimal place shown.
• Two levels of resistance:
  • First level: Lower resistance, used to aspirate liquid.
  • Second level: Higher resistance, used to dispense liquid completely.

Micropipetting Technique

• Attach appropriate tip snugly before use.
• Aspirate liquid:
  • Press piston to the first level.
  • Dip tip in liquid and gently release thumb to fill.
• Dispense liquid:
  • Place tip at container edge.
  • Release to the first level, then second level if needed.

Important Practices

• Always use a tip; avoid touching tips due to potential chemicals or microbes.
• Dispose of tips using the tip ejector to prevent contamination.
• Never hold micropipette upside down when filled to avoid damage.

Multi-Channel Pipetting Technique

• Fill trough with liquid for easier aspiration.
• Ensure all channels pick up equal liquid.
• Use 96-well plates for dispensing:
  • Align correctly with wells (e.g., 8 channels for 8 wells).
• Dispose of all tips using the ejector function efficiently.

Conclusion

• Practice makes perfect; watch demonstrations or videos as needed.
• Prepare for lab sessions with confidence in micropipetting skills.

Note: This guide serves as a fundamental reference for beginners to understand and practice micropipetting effectively in laboratory settings.