The high viscosity and tendency to stick to surfaces of viscous liquids make pipetting them difficult. However, accurate pipetting of viscous liquids is achievable with the right technique and pipette tip selection. When pipetting viscous liquids, the following rules need to be observed:

l Use wide-bore pipette tips: Viscous liquids can enter and exit wide-bore pipette tips more readily due to their larger internal diameter. This can lessen the amount of liquid that stays in the tip after pipetting in addition to increasing accuracy.

l Pre-wet the pipette tip: You can lessen the amount of liquid that sticks to the inside of the pipette tip by prewetting it with a tiny amount of the viscous liquid. This can reduce the possibility of air bubbles forming in the tip and increase accuracy.

l Use a slow pipetting speed: One important tip for pipetting viscous liquids is to start slowly. By doing this, the liquid will have more time to enter and exit the tip and air bubbles will be less likely to form.

l Use reverse pipetting: Reverse pipetting is a method for increasing the accuracy of pipetting viscous liquids. Fill the pipette tip with the desired amount of liquid before reversing it. After that, gradually add more liquid to the reservoir. The residual liquid will be drawn out with the help of the vacuum that is created in the tip when you expel the liquid.

l Touch the pipette tip to the side of the vessel: To remove any leftover liquid, touch the tip of the pipette to the vessel's side after expelling the liquid. By doing this, you can make sure that the right amount of liquid is being dispensed.

l Change pipette tips frequently: It is imperative to replace the pipette tips frequently when pipetting viscous liquids. This is due to the fact that viscous liquids may stick to the inside of the tip and make pipetting less accurate.

l Use a positive displacement pipette: When pipetting extremely viscous liquids, a positive displacement pipette may be required. For viscous liquids, positive displacement pipettes are more accurate than air displacement pipettes because they dispense liquid using a plunger.

l Calibrate your pipette: It is imperative to calibrate your pipette on a regular basis to guarantee that the appropriate volume of liquid is being dispensed. This is crucial when pipetting viscous liquids in particular.

You can pipette viscous liquids with more accuracy and precision if you adhere to these best practices.