Table of Contents
- 1 Why is my pipette leaking?
- 2 When transferring liquid using a pipette sometimes the liquid leaks out what should you do when that happens?
- 3 What happens if you pipette too fast?
- 4 How do I stop a dripping pipette?
- 5 Why is it that liquid remaining at the tip of the pipet with TD marks should not be forced out?
- 6 Why is it important to keep your automatic pipette upright when there is liquid in the tip?
- 7 What is a possible cause of error when pre wetting is not done?
- 8 What are the five common pipetting errors?
- 9 What happens if you don’t pause the pipette tip?
- 10 What should I do if I have liquid in my pipette?
- 11 What’s the best way to prevent contamination in pipetting?
Why is my pipette leaking?
Your pipette could be dripping or leaking because there is corrosion in your pipette. This means that your seal is no longer working correctly, therefore you need internal cleaning and maintenance of your pipette. Your pipette might need proper lubrication. Sometimes dripping or leaking is also caused by a shaft issue.
When transferring liquid using a pipette sometimes the liquid leaks out what should you do when that happens?
pipette, use pressure from a pipette bulb to blow out the residual drop. Do not blow out the residual drop when using a T.D. pipette. If a volumetric pipette is used, the liquid should be withdrawn with suction to the marked line above the glass bulb (indicated in Figure 1.25d).
What shouldn’t you do when there is liquid in a pipette tip?
Leave the tip still in the liquid for about one second after aspirating the sample. It takes a moment for the liquid in the tip to finish moving after the plunger stops, so failure to do so will cause the volume to be too low. Make these pauses as consistent as possible.
What happens if you pipette too fast?
Variation in Pipetting Speed Aspirating too quickly can cause inaccuracies with viscous liquids, lead to air bubbles, or liquid contact with the pipette filter, increasing the chance of contamination. Dispensing a liquid too quickly can lead to splatter or disrupt cells on the bottom of a microplate.
How do I stop a dripping pipette?
One technique to reduce or even stop the dripping is to achieve a higher percentage of humidity in the air cushion. This is done by pre-wetting the pipette tip and thereby saturating the air cushion.
Why did the pipette change tips every time?
Sample-to-sample contamination (or carry-over contamination) occurs when aerosol or liquid residue from one sample is carried over to the next sample. This may take place, for example, when the same pipette tips are used multiple times. To avoid carry-over contamination: Always change the pipette tip after each sample.
Why is it that liquid remaining at the tip of the pipet with TD marks should not be forced out?
A volumetric pipet should not be “blown out” to eject all liquid at the tip because volumetric pipets are calibrated in a manner that takes into account the solution which remains at the tip due to surface tension.
Why is it important to keep your automatic pipette upright when there is liquid in the tip?
Hold the pipette in a vertical position during pipetting and store the pipette in an upright position. This prevents liquids from running into the pipette body. Use filter tips or positive displacement tips to prevent aerosol transfer from the sample into the pipette body.
How do you stop pipetting errors?
Take Care of Your Pipette
- Have Your Pipette Serviced Every 6–12 Months.
- Check Your Pipette for Damage Daily.
- Clean Your Pipette Each Day Before Use.
- Store Your Pipette Vertically, Using a Pipette Holder.
- Never Put Your Pipette on Its Side With Liquid in the Tip.
- Use Well-Fitting Tips.
What is a possible cause of error when pre wetting is not done?
Failure to pre-wet the tip increases evaporation within the tip air space, which can cause significantly lower delivery volumes.
What are the five common pipetting errors?
Common pipetting errors include:
- Failure to Pre-Wet Pipette Tip.
- Disregarding Temperature.
- Tip Wiping.
- Choosing the Wrong Pipetting Mode.
- Working Too Quickly.
- Pipetting at an Angle.
- Using the Wrong Pipette Tips.
What is the reason for aspirating and dispensing the mixture repeatedly?
To reduce the amount of evaporation, a pipette tip should be prewetted several times by aspirating the sample and dispensing it back into the sample vessel. This increases the humidity inside the pipette tip, reducing the amount of sample evaporation and thereby the accuracy of the pipetted volume.
What happens if you don’t pause the pipette tip?
After aspirating, failure to pause with the pipette tip in the liquid can lead to under-delivery. This is because the liquid is not still at first insertion and requires about one second to settle. Touching the pipette tip to the container sides during aspiration results in loss of sample.
What should I do if I have liquid in my pipette?
Avoid turning the pipette on its side when there is liquid in the tip. Liquid might go to the interior of the pipette and contaminate the pipette. Avoid contamination to or from fingers by using the tip ejector and gloves. Store pipettes in an upright position when not in use.
What happens if you pull a pipette straight out of the container?
Pulling the pipette straight out of the container can minimize error. Failure to choose the proper tips for a given type of pipette can lead to an inadequate seal between the pipette and tip, causing leakage and sample loss.
What’s the best way to prevent contamination in pipetting?
Hold the pipette in a vertical position during pipetting and store the pipette in an upright position. This prevents liquids from running into the pipette body. Use filter tips or positive displacement tips to prevent aerosol transfer from the sample into the pipette body.