CHAPTER 2 Flashcards
Proper pipetting techniques
Recommended for aqueous solutions, such as buffers, diluted acids, or alkalis.
Forward Technique
This technique is commonly used when pipetting and mixing a sample or reagent into another liquid.
Forward Technique
- Press the operating button to the first stop.
- Dip the tip into the solution to a depth of 1 cm, and slowly release the operating button. Withdraw the tip from the liquid, touching it against the edge of the reservoir to remove excess liquid.
- Dispense the liquid into the receiving vessel by gently pressing the operating button to the first stop. After one second, press the operating button to the second stop. This action will empty the tip. Remove the tip from the vessel, sliding it along the wall of the vessel.
- Release the operating button to the ready position
Forward Technique
This is for standard pipetting
Forward Technique
This is for solutions with high viscosity or tendency to foam
Reverse Technique
This technique is commonly used with air displacement pipettes
Reverse Technique
This is recommended for precisely pipetting small volumes.
Reverse Technique
This avoids the risk of sample splash, foaming, or bubble formation.
Reverse Technique
- Press the operating button to the second stop.
- Dip the tip into the solution to a depth of 1 cm, and slowly release the operating button. This action will fill the tip. Withdraw the tip from the liquid, touching it against the edge of the reservoir to remove excess liquid.
- Dispense the liquid into the receiving vessel by depressing the operating button gently and steadily to the first stop. Hold the button in this position. Some liquid will remain in the tip, and this should not be dispensed. Remove the tip by sliding it along the wall of the vessel.
- The liquid remaining in the tip can be pipetted back into the original solution or thrown away with the tip.
- Release the operating button to the ready position.
Reverse Technique
This is for repeat pipetting of the same volume
Repetitive Pipetting Technique
This technique is ideal for adding reagents into tubes or wells of microplates
Repetitive Pipetting Technique
- Press the operating button to the second stop.
- Dip the tip into the solution to a depth of 1 cm, and slowly release the operating button. Withdraw the tip from the liquid, touching it against the edge of the reservoir to remove excess liquid.
- Dispense the liquid into the receiving vessel by gently pressing the operating button to the first stop. Hold the button in this position. Some liquid will remain in the tip, and this should not be dispensed. Remove the tip by sliding it along the wall of the vessel.
- Continue pipetting by repeating steps 2 and 3.
Repetitive Pipetting Technique
This technique is used for pipetting heterogeneous samples, such as blood or serum.
Heterogeneous Sample Pipetting Techniqu
Pre-rinsing the tip is not possible, and the full sample should be dispensed for accurate analysis.
Heterogeneous Sample Pipetting Techniqu
Heterogeneous Sample Pipetting Techniqu