The filter in a pipette tip serves to prevent the contamination of the pipette and sample by aerosols and liquids. This is especially relevant in applications involving sensitive biological samples, PCR (polymerase chain reaction), and other molecular biology techniques. The filter is a physical barrier located at the top of the pipette tip, and it typically consists of a hydrophobic material.
Here are some key functions of the filter in a pipette tip:
- Aerosol Barrier: The filter prevents the entry of aerosols into the pipette during liquid aspiration. Aerosols can carry contaminants, including nucleic acids or enzymes, which may compromise the integrity of sensitive experiments, such as PCR reactions.
- Liquid Barrier: The hydrophobic nature of the filter repels liquids, acting as a barrier to prevent any liquid from entering the pipette shaft. This is important for maintaining the accuracy of pipetting and preventing the contamination of the pipette’s internal components.
- Preventing Cross-Contamination: The filter helps to minimize the risk of cross-contamination between samples. As the pipette tip is ejected after each use, any potential carryover of contaminants is disposed of with the used tip, reducing the risk of contamination between different samples.
- Protecting the Pipette: The filter also acts as a protective barrier for the pipette’s internal components. By preventing liquids and aerosols from entering the pipette shaft, the filter helps maintain the integrity and performance of the pipette over time.
It’s important to note that filter tips are not suitable for all applications. In some cases, particularly when working with viscous liquids, the use of filter tips may not be recommended. Researchers should follow manufacturer guidelines and choose the appropriate type of pipette tip for their specific application to ensure accurate and contamination-free liquid handling.