Mastering Pipetting Techniques

What is the primary purpose of forward pipetting?

• To filter impurities from a solution.

• To measure the temperature of a liquid.

• To mix two different liquids together.

• To accurately transfer a specific volume of liquid.

Describe the steps involved in reverse pipetting.

• Reverse pipetting is a technique used to accurately dispense viscous or volatile liquids.

• Reverse pipetting is a method for measuring temperature in liquids.

• Reverse pipetting involves drawing liquid into the pipette and discarding it immediately.

• Reverse pipetting is only used for solid samples.

What precautions should be taken when pipetting volatile solutions?

• Pipette without gloves

• Use open containers for storage

• Use a fume hood, secure pipette tips, minimize air exposure, and pre-wet tips.

• Avoid using a fume hood

How does the viscosity of a solution affect pipetting technique?

• All solutions require the same pipetting speed regardless of viscosity.

• Viscosity has no impact on pipetting technique whatsoever.

• Higher viscosity solutions require slower, more controlled pipetting techniques for accuracy.

• Higher viscosity solutions can be pipetted faster without issues.

What is the correct way to perform forward pipetting?

• Immerse tip, press plunger to first stop, move to destination, release plunger, press to second stop.

• Press plunger to second stop, immerse tip, release plunger, move to destination, press to first stop.

• Press plunger to first stop, move to destination, immerse tip, release plunger, press to second stop.

• Press plunger to first stop, immerse tip, release plunger, move to destination, press to second stop.

In reverse pipetting, what is the significance of the second stop?

• It prevents contamination by not touching the liquid.

• It allows for faster pipetting without accuracy concerns.

• It is used to measure solid samples instead of liquids.

• It ensures complete expulsion of the liquid for accurate volume delivery.

Why is it important to pre-wet the pipette tip when working with viscous solutions?

• Pre-wetting the pipette tip increases the volume of the sample taken.

• Pre-wetting the pipette tip improves accuracy and consistency when handling viscous solutions.

• Pre-wetting the pipette tip prevents contamination from air bubbles.

• Pre-wetting the pipette tip is only necessary for aqueous solutions.

What are the potential consequences of not using the correct pipetting technique?

• Faster experimental processes.

• Improved accuracy in measurements.

• Inaccurate measurements and compromised experimental results.

• Enhanced data visualization techniques.

How would you pipette a volatile solution to minimize evaporation?

• Store the solution in a hot place before pipetting to reduce viscosity.

• Use a narrow-tipped pipette and work quickly in a cool environment.

• Use a wide-bore pipette and work slowly in a warm environment.

• Pipette the solution directly from an open container to allow maximum exposure.

What is the best practice for pipetting very viscous solutions?

• Dilute the solution before pipetting.

• Use a larger bore pipette or a positive displacement pipette.

• Use a standard pipette with a narrow tip.

• Use a vacuum pipette for better suction.