How to avoid common misunderstandings in the use of low-binding pipette tips?

Low binding pipette tips can significantly reduce sample residues due to their hydrophobic inner surface design, and are particularly suitable for handling expensive reagents, viscous liquids or trace samples (such as proteins and nucleic acids). However, if they are not operated properly, they may still affect the accuracy and repeatability of the experiment. The following is an analysis of common errors and solutions in use in combination with laboratory operating specifications:

Misunderstanding 1: Ignoring the pre-rinsing of the tip

Wrong operation: Directly aspirate the sample and omit the pre-rinsing step.

Impact: Although low-binding pipette tips can reduce residues, for samples such as serum, protein or organic solvents, their inner walls may still form a micro-liquid film due to surface tension, resulting in a low initial pipetting volume.

Correct approach: Before formal pipetting, repeat the aspiration-discharge 2 to 3 times with the same sample to form a stable liquid film layer on the inner wall of the tip (except for high-temperature/low-temperature liquids).

Misunderstanding 2: The aspiration speed is too fast or the angle is tilted

Wrong operation: Aspirate the liquid quickly or the pipette is tilted more than 20°.
Impact:

Pipette too fast: bubbles or back suction (liquid rushes into the pipette and contaminates the piston);
Pipette tilted: changes the liquid surface pressure, resulting in inaccurate pipetting volume and increased residual volume. Correct approach:
Pipette slowly and release slowly: operate at a constant speed and control the piston release speed;
Hold vertically: keep the tilt angle ≤20° when the pipette tip is immersed in the liquid surface.
Misunderstanding 3: Ignoring the operational differences of viscous liquids
Wrong operation: Use the same pipetting speed as ordinary liquids for high-viscosity samples (such as glycerol and cell suspensions).
Impact: Viscous liquids flow slowly on the inner wall of the pipette tip, and rapid discharge will cause a significant increase in residual volume, offsetting the advantages of the low adsorption design.
Correct approach:

Extend the immersion time: stay in the liquid surface for 1 second after aspirating before removing it, and pause for 1 second before pressing the second gear to blow the liquid when discharging;
Choose a wide-mouth pipette tip: For macromolecules or cell samples, use a wide-mouth low-adsorption pipette tip (70% larger than the standard aperture) to reduce shear force.
Misconception 4: Hitting hard when installing the tip
Wrong operation: repeatedly hitting the pipette handle to "tighten" the tip.
Effect: Long-term impact will wear the pipette sealing components, destroy the airtightness, and cause leakage or volume error.
Correct method: insert the pipette vertically into the tip, press lightly, and slightly rotate left and right to fit.

Misconception 5: Incorrect storage or reuse
Wrong operation:

Put the pipette flat when there is residual liquid in the tip;
Reuse disposable low-adsorption tips to save costs. Impact:
Putting flat causes backflow of liquid to corrode the piston spring;
Reuse may affect accuracy due to cross contamination or structural deformation. Correct method:
Discard the tip immediately after pipetting, and hang the pipette vertically;
Reuse is strictly prohibited, especially when it comes to sensitive experiments such as PCR and isotopes.
Professional advice: Maximize the advantages of low-retention tips
Match the properties of liquids:
Volatile liquids (such as chloroform): Avoid using ordinary low-retention tips and use solvent-safe tips or external piston pipettes designed for volatile reagents.
Calibration verification:
Regularly weigh the weight of pure water pipetted with an analytical balance (1mL=0.9982g at 20℃) to verify whether the actual volume meets the standard.
Key points summary: Low-retention tips improve accuracy by reducing sample loss, but if the details of the operation are ignored, it may still be counterproductive. Standardized installation, speed control, adaptation to sample characteristics and strict one-time use are the basis for achieving high repeatability experiments.