Contamination can significantly impact the accuracy and reliability of your laboratory results. Here are some key steps to prevent it using pipette tips:  

General Prevention Measures

Use a new tip for each sample: This is the most fundamental way to prevent cross-contamination between samples.

Avoid touching the tip with your fingers: Your hands are a major source of contamination. Wear gloves and avoid touching the tip's exterior.  

Use filtered tips: These tips contain a porous filter that prevents aerosols and liquid droplets from entering the pipette, reducing the risk of contamination.  

Proper pipetting technique: Ensure you are using the correct pipetting technique to avoid creating aerosols or drawing liquid into the pipette body.

Regularly clean the pipette: Follow the manufacturer's instructions for cleaning and disinfecting your pipette to prevent buildup of contaminants.

Specific Contamination Types

Sample-to-sample contamination

Use filtered tips.

Change tips between samples.

Consider using aerosol-resistant tips.

Sample-to-pipette contamination

Hold the pipette vertically during pipetting to prevent liquid from entering the pipette body.  

Use filter tips.

Avoid immersing the tip too deeply into the liquid.

By following these guidelines, you can significantly reduce the risk of contamination and ensure the accuracy of your experiments.