The Different Types Of Pipette Tips (and When To Use Them)

By Author: Accumax
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1- Pipette tips of various sorts
Pipette tips come in non-sterile, sterile, filtered, unfiltered, long, short, low retention, and wide bore varieties. So, let's look at what each of these parameters is useful for:

1.1 Non-sterile versus sterile

It goes without saying that sterile pipette tips should be used in applications where sterility is critical. But, in order to save money, may you buy non-sterile tips and autoclave them yourself? Theoretically, the answer is yes. You must, however, ensure that the manufacturer declares them to be autoclavable and be careful of the following:

Inadequate quality control

Manufacturers should validate their sterilizing method and conduct regular quality checks. Individual labs, on the other hand, rarely assess the effectiveness of their autoclaving technique, which can result in compromised samples.

RNase and DNase are present in autoclaved tips.

Autoclaved tips are sterile, which implies they are free of living organisms but not necessarily of RNase and DNase. If you need to run sensitive experiments that need this, use sterile pipette ...
... tips from a manufacturer who can confirm that their tips are RNase and DNase-free.

1.2 Filtering Tips
Aerosols are produced inside the pipette tip every time you aspirate liquid. These aerosols may contaminate your pipette and, as a result, your following samples if you do not utilize filter tips - even if you replace tips in between.

When performing PCR applications, for example, cross-contamination of samples by aerosols in the pipette could result in false positive results, as even trace amounts of DNA from a prior sample could be amplified. For your own safety and the longevity of your pipette, it's especially crucial to utilize filter pipette tips when handling liquids that could damage your pipette, such as radio-labeled or corrosive samples.

The following liquids should always be pipetted with filter tips, as they may contaminate or harm your pipette:

Solutions for RNA/DNA
Infectious specimens
Radiolabeled specimens
Samples that are volatile, corrosive, or viscous
Acids or bases that are extremely strong

Finally, filter pipette tips might be effective for educating new lab staff. Spending extra money on filter tips until your colleagues become accustomed to your instruments is a fantastic idea that generally pays for itself because you can avoid pipette contamination or damage from liquid entering the pipette's bottom end.

1.3 Prolonged tips
Have you ever risked cross-contamination by inserting the shaft of your pipette into a tube to reach the bottom with a regular tip? Many manufacturers offer extended-length pipette tips ideal for labware such as microcentrifuge tubes or deep well blocks to prevent this issue.

1.4 Quick hints
Short pipette tips provide two benefits. First, they help with small well targeting, such as when manually pipetting into a 384 or 1536 well plate with a multichannel pipette. Second, they increase ergonomics by allowing you to pipette closer to the bench, decreasing arm strain.

1.5 Tips for Poor Retention
Low retention pipette tips, as the name implies, retain less liquid, resulting in more precise and consistent findings while preserving valuable reagents. They are, however, more expensive than regular tips, so you should know when to use them. In a series of tests, our in-house application scientist revealed that both standard and low retention tips give optimal liquid recovery while pipetting water, but create dramatically different outcomes when handling viscous or low surface tension solutions.1 As a result, low retention tips are appropriate for pipetting highly concentrated, and thus viscous, samples during:

PCR, cloning, sequencing, and other uses involving DNA and RNA
Protein purification, SDS-PAGE, and other protein analysis applications

Is every low retention tip the same?
When manufacturing low-retention pipette tips, producers often add a silicone coating or utilize a different polypropylene blend to their conventional tips. Both approaches keep viscous or low surface tension liquids from spreading out and 'watering' the inside wall of the tips, but the latter has one significant disadvantage: a silicone coating might wash or leach out with your sample. To ensure that liquid repellents do not contaminate your samples, use pipette tips made of a polypropylene blend with enhanced hydrophobic characteristics.

1.6 tips with a wide bore
When cellular samples are squeezed through the tiny aperture of ordinary pipette tips, they might be destroyed. When transferring cellular samples, such as fragile cell lines or other fluid materials, use large bore tips. These tips' larger orifices prevent (cell) shearing and reduce flow resistance.

2 Why is tip quality and fit so important?
Now that you know when to use each tip type, let's talk about tip quality and fit. Pipette tips of poor quality or poorly fitted can have a significant impact on the reproducibility of your results. This implies you'll have to redo experiments, wasting time and money. Furthermore, repeating tests means more pipetting, which puts strain on your arm, wrist, and fingers, especially if you utilize poorly fitted tips that demand high attachment and ejection forces, and can eventually lead to repetitive strain injuries.

2.1 How to Evaluate Tip Quality
The polypropylene blend is the primary factor impacting the quality of pipette tips. High-quality tips are composed of virgin polypropylene, which contains no plastic or metal additions that could contaminate your samples. When purchasing colored tips, it is especially crucial to ensure that the producer does not utilize metal additives, as metal compounds are frequently found in dyes.

The injection molding machine is the second aspect that influences quality. The smallest batch-to-batch or within-batch changes, such as deviations in straightness, molding flash, or streaking, have a negative impact on your results' accuracy and precision. Because these anomalies are often invisible to the naked eye, it is best to avoid purchasing the cheapest tips on the market to limit the possibility of erroneous and imprecise findings.

2.2 Finding a Properly Fitting Tip
Because tip shapes differ, not every tip will fit your pipette. Ideally, you should only use the tips specified by the manufacturer of your pipette. If you utilize tips that have not been verified and confirmed by the manufacturer, you should always gravimetrically test them to guarantee that they yield reliable results.

3 Final Thoughts
Purchasing good quality, perfectly fitting pipette tips may appear to be more expensive at first glance, but it will save you a lot of time, money, and health risks in the long run. However, whether you can work with non-sterile ordinary tips or whether you need to invest in tips with features such as increased hydrophobicity or larger orifices depends on your needs. Follow our suggestions above to answer this question every time you start a new application, and your pipette tips will never damage your lab work again.

Accumax provides mechanical & electronic pipettes, bottle top dispensers, pipette controllers, pipette tips, PCR consumables, deep well plates, centrifuge tubes, transfer pipettes & more.https://accumaximum.com/