How to prevent liquids from dropping out
One technique to reduce or even stop the dripping is to achieve a higher percentage of humidity in the air cushion. This is done by pre-wetting the pipette tip and thereby saturating the air cushion. When using low volatile liquids such as 70 % Ethanol or 1 % acetone, aspirate and dispense the sample liquid a minimum of 3 times, before aspirating the sample volume you want to transfer. If the concentration of volatile liquid is higher, repeat these pre-wetting cycles 5-8 times. However, with very high concentrations such as 100 % ethanol or chloroform, this won’t be enough. It’s best to use another type of pipette: a positive displacement pipette. These pipettes use tips with an integrated piston without an air cushion. The sample is in direct contact with the piston and there is no risk of dripping.
Become a master of pipetting
You can easily improve your accuracy when pipetting volatile liquids by choosing the correct technique or changing the tool you are using. Additionally, you will increase safety by avoiding spillage and simplify your workflow. If you want to learn more on correct pipetting, watch our Youtube video tutorial How to pipette correctly