A Guide for Selecting Laboratory Pipette Tips

Selecting high-quality pipette tips is crucial for ensuring accuracy and precision in your pipetting tasks. When deciding on the type of tip to use, accuracy and precision should be your primary considerations. Any variations in the shape of the pipette tip, whether within or between batches, can lead to inaccuracies in your pipetting. This issue stems from deficiencies in build quality and quality control, both of which come at a cost in any manufacturing process. Incompatibility between the tip and your specific pipettor can also compromise accuracy. Additionally, poor sealing between the pipettor barrel and the tip may result in air escaping, thereby hindering the aspiration of the correct volume of liquid.

While universal or pipettor-specific tips are viable options if provided by the pipettor manufacturer, opting for high-quality universal tips is often the optimal choice for your pipettor and application. Professional tip manufacturers typically specialize more extensively than pipettor manufacturers, ensuring superior quality and performance. These universal tips are compatible with the majority of micropipettors available in the market, offering versatility and reliability across various laboratory settings.

Filtered, non-barrier, and barrier pipette tips are tailored for specific conditions. While non-barrier tips are suitable for standard laboratory procedures, barrier tips are essential when handling substances that could contaminate the pipettor, such as bacteria, viruses, or corrosive chemicals, safeguarding both the pipettor and the sample.

For numerous non-sensitive applications, both filtered/non-barrier and standard pipette tips suffice. These tips are commonly utilized in laboratory tasks such as loading agarose gels and separating plasmid DNA. Non-barrier tips, being cost-effective and versatile, serve as the cornerstone of laboratory work.

These tips are obtainable in bulk packaging, pre-racked configurations, or reloadable options, facilitating convenient storage and reuse. While bulk and most reloadable tips may not be sterile, they can be sterilized along with their storage containers in an autoclave.

Aerosol Barrier Tips, also referred to as filtered pipette tips, feature a filter located at the proximal end of the tip. This filter serves to shield the pipettor from aerosols and prevent the inhalation of volatile or viscous solutions into the pipette barrel, which could potentially contaminate and harm the pipettor. Typically, these tips come pre-sterilized and are devoid of DNase/RNase contaminants.

However, it's important to note that the term "barrier" may be somewhat misleading for certain types of tips. While high-end tips can indeed provide a true sealing barrier, most filters only slow down the liquid entering the pipette tube. Despite this, filtered barrier tips are preferred for sensitive applications like qPCR, where maintaining sample integrity is paramount. The barrier effectively prevents sample residue in the pipettor from contaminating the PCR, ensuring more reliable results.

It's advisable to conduct PCR positive and negative controls to detect any potential sample residue. Pipettor contamination often occurs when new laboratory personnel inadvertently aspirate liquid into the pipettor itself. Discarding tips after each use proves to be a more straightforward and cost-effective solution than sending the entire pipettor for repair, especially considering the presence of liquid in the piston.

Low Retention/Low Adsorption Tips: Regardless of the tip type you select, low retention remains a crucial attribute. These tips, as their name implies, retain minimal amounts of liquid. If you've ever observed standard pipette tips, you may have noticed residual liquid left behind after pipetting. Low retention tips mitigate this issue by incorporating hydrophobic plastic additives that discourage liquid adherence within the tip.

Cost considerations for pipette tips mirror those of most products – you typically get what you pay for. Well-crafted and properly installed tips are essential for achieving accuracy, precision, and ease of use. Investing in high-quality tips engineered for optimal performance is advisable unless you're content with less precise micropipettes. When considering additional features such as gradation markings or barriers, evaluate whether the added benefits justify the cost. Opt for tips with these features when necessary for your experiment, as your pipettor and tips collaborate to deliver accurate and precise measurements.

The range of available tips is extensive, but utilizing this guide will assist you in selecting the appropriate tip for each application, resulting in clearer and more dependable results.