Choose the Best Pipette Tips for You Lab

Pipette tips should be used with pipettes and are mainly used in all pipetting scenarios. In the laboratory, pipetting of liquids is the basic operation of all experiments and is one of the laboratory's most commonly used classes of consumable products. The choice of laboratory pipette tips depends on several factors, and choosing the right pipette tip is critical to the accuracy of liquid measurements.

Common questions about pipette tips: do pipette tips dissolve in DMF? What materials of pipette tips can be used for sulfuric acid and hydrochloric acid, and how do I choose? Next, you will learn about the types of pipette tips and materials and how to select the right pipette tips for your experiment.

What materials are pipette tips made of?

1. Polypropylene (PP): This is the most common material for pipette tips. It is suitable for general laboratory operations and cannot be used for pipetting concentrated sulphuric acid, strong acids, strong bases and some organic solvents such as methylene chloride, benzene and toluene.

2. Polyethylene (PE): PE pipette tips are less durable than PP and are therefore less commonly used.

3. Polytetrafluoroethylene (PTFE): Suitable for experiments requiring high precision and safety, but the disadvantage is that they are expensive and less durable.

4. Polystyrene (PS): Polystyrene tips have a high degree of transparency but are more brittle and less commonly used than polypropylene tips. They are often used in applications where optical clarity is required.

5. Conductive polypropylene: Tips with added conductive material to prevent static electricity. It is often used in electronics or experiments that require high-precision liquid handling.

6. Filtered Tips: These tips add a filter to regular polypropylene tips. This prevents aerosols and liquids from contaminating the inside of the pipette and is particularly suitable for PCR and micro-sample handling.

Many different materials are used in pipette tips, each with its application. Let's look at some of the most common questions about several solvents in the laboratory.

Do pipette tips dissolve in DMF

DMF is a strong polar organic solvent soluble or destructive to many plastics. PTFE has excellent chemical resistance to DMF and is ideal for handling DMF.

Polypropylene has relatively good resistance to DMF and will not rapidly dissolve or degrade. However, prolonged exposure to DMF may result in tip softening or deformation.

PS and PE pipette tips are less resistant to DMF and can soften or dissolve quickly, making them unsuitable for pipetting DMF.

Is pipette safe for sulfuric acid

Only PTFE can ensure safe pipetting for high concentrations of sulphuric acid.

Polypropylene has good resistance to dilute sulphuric acid (10-20%) and is safe to use. Polypropylene is subject to corrosion and degradation and is therefore not recommended for long-term use in high concentrations of sulphuric acid.

Is pipette acid proof

The acid resistance of a pipette depends on its tip material. Polypropylene and polyethylene are resistant to dilute acids but less to concentrated acids. Polytetrafluoroethylene (PTFE) is extremely resistant to all acid concentrations and is the best choice when handling acids.

Types of pipette tips

Types of pipette tips are available in bulk, in boxes and individually packaged.

Pipettes are classified by volume (5 ml to 10 ml), micropipettes (0.5 µL to 1,250 µl) and ultra-micropipettes (0.5 µL - 20 µL). Other categories most commonly used in laboratories are the following:

Standard tips

Standard pipette tips usually refer to specifications that conform to international standards, such as ISO 8655. These standards define parameters such as tip size, volume, accuracy, etc. and ensure that different brands of pipettes and tips can be used interchangeably. Sterile standard tips are used for applications with the highest purity requirements.

Sterile filter tips

When the method is sensitive to cross-contamination or when samples may contaminate the pipette, filter tips are used to prevent the spilling of liquids into the pipette and to reduce aerosol penetration. Filter tips are suitable for low-volume applications such as forensic science, genetic research, PCR and radioisotope sampling, effectively preventing cross-contamination.

Extended Tips

Extended tips keep samples safe and reduce residual contamination by allowing them to reach the bottom of tubes, vials and flasks without the pipette barrel touching the container wall. They are suitable for deep penetration into long or narrow containers.

Low-retention pipette tips

Polymer technology makes the inner surface of pipette tips more hydrophobic, significantly reducing sample loss due to adhesion. The advantage is improved pipetting performance and savings in expensive reagents.

How to choose the right pipette tips

The following points need to be considered when choosing the right pipette tip for your application: tip material, tip precision and sterility and filter type.

1. Transfer volume - the selected tip capacity matches the required sample volume.

2. Tip material - choose the appropriate tip material, e.g. polypropylene, polyethylene, PTFE, etc., according to the nature of the liquid to be aspirated (e.g. pH, polarity, etc.).

3. Liquid properties - volumetric accuracy may depend on the type of liquid you are transferring, especially when working with viscous, corrosive, or volatile liquids.

4. Sterility: For demanding samples, it is recommended to choose sterile tips or tips that can be sterilized in a sterilizer.

5. Tip quality and availability - In addition to choosing the pipette itself, you need to ensure that you have high-quality pipette tips available for your experiment.

Conclusion:

Quality pipette tips not only ensure precise liquid transfer, but also prevent cross-contamination and protect samples. Choose the right tip material, such as polypropylene or PTFE, and the right filter tip for your specific experimental needs.

Ensure that pipette tips remain sterile before use through proper sterilisation steps to further ensure the accuracy of experimental results. Attention to detail and the selection of high-quality tips will have a profound impact on the success of your experiments.