Three Tests to Help You Get Better Low-Absorption Pipette Tips

Three types of pipette tips

There are three main types of tips: ordinary tips, filter tips, and low-adsorption tips.
1. Ordinary pipette tip
Tips and tip boxes can be autoclaved at 121℃/15psi. It is suitable for pipettes of different brands and models with good adaptability. The tip body has good transparency and scale line, which is easy to confirm and observe when using. It is resistant to organic solvents. Tips of different capacities are designed in different colors for easy distinction. It has a wide range of applications. In general laboratories, ordinary tips are basically suitable for all pipetting. This is an economical and cost-effective type of tip.

2. Filter pipette tip
Some complained that when the pipette tip is disassembled for maintenance, it is always horrible inside. The stainless steel piston is corroded and rusty. How to solve it? At this time, consider using filter tips. The price is a bit more expensive than ordinary pipette tips. We often use it in molecular biology, virology, and cytology experiments.

The filter tip is an upgraded version of the ordinary tip. The filter element is added to the ordinary tip, and the pore size is optimized to ensure the barrier effect and good air permeability. The color is transparent. The filter tip has three major benefits: 1. Ensure the safety of experimenters: it can reduce the spread of harmful products and ensure the personal safety of operators to a large extent. 2. Guarantee sample safety: no heat source, no Dnase/Rnase, no PCR inhibitors, to prevent cross-contamination. 3. Ensure the safe use of the pipette: avoid liquid rushing into the cavity, maintain precision and accuracy, and extend the service life of the electric pipette.

3. Low adsorption pipette tip
Low adsorption pipette tip, such as conductive tips, With hydrophobic treatment in the surface, the low-adsorption tip is able to reduce the surface tension, which can greatly reduce sample loss, avoid protein absorption, and facilitate the removal of viscous materials, genomic DNA, or delicate cell cultures, and it is the best guarantee for obtaining highly accurate experimental results. It is generally used for experiments that require high sensitivity, or precious samples or reagents that are easy to remain, which can greatly reduce sample loss and improve recovery.

20ul-filter-pipette-tips-sterile-400x400 20ul-filter-pipette-tips-400x401 conductive filter automation tips

Three tests to check low-absorption pipette tip

The accuracy and precision of pipetting not only require the matching of the tip and the pipette, but also a tip suitable for the liquid. When using standard pipette tips (PP) to pipette liquids with low surface tension, it is easy to leave a membrane on the surface of the pipette tips (such as liquids containing detergents). The residual liquid will lead to inaccurate and inconsistent pipetting results, and at the same time, some expensive samples will be lost. Different manufacturers use different technologies to manufacture low-adsorption tips, so their consistency, degree of hydrophobicity, and chemical resistance are different. HAWACH describes three methods to test the quality.

1. Absorbance test
In the absorbance test, after discharge, a staining reagent (green food dye dissolved in distilled water) is used to decide the residual liquid in the pipette tip. Use the maximum nominal volume of the test tip to draw the green reagent. Then drain the liquid directly back into the container. Next, rinse the tip with distilled water at the maximum capacity of the tip 5 times. Then use a spectrophotometer to measure the absorbance of the rinse solution and compare the result with the reference reagent. The absorbance of the rinse liquid is directly related to the amount of liquid remaining in the tip.

2. Chemical resistance test
1000 μl solvent: Use a 1000 μl pipette tip to pipet isopropanol, acetonitrile and dimethylformamide 20 times. Rinse the tip three times with distilled water. Then use the dyeing liquid as a reagent, and use the absorbance test to analyze the effect of this treatment on the performance of the low-absorption tips. The test is repeated on 6 tips for each solvent. Compare the results of chemically treated tips with untreated standard tips and low-absorption tips.

3. Gravimetric method
After pipetting, use gravimetric analysis to measure the amount of liquid remaining in the pipette tip. Place the small glass container filled with reagents on the balance and set the weight to zero. Then draw a certain amount of reagent from the container and release it back, and record the balance reading showing the amount of liquid remaining in the tip. Repeat this operation for each detergent solution listed above.

Low-absorption tips have obvious advantages over ordinary tips when pipetting liquids containing detergents, and can greatly reduce the amount of liquid remaining in the tips after pipetting. There are significant differences in the performance of various low-absorption tips on the market. If you cannot decide which one is more suitable for you, contact HAWACH for a better solution.