Preventing cross-contamination

Pipette-to-sample

A contaminated pipette or contaminated tips can cause contamination of samples.

Prevention:

  • Use filter tips.
  • Change the tip after pipetting each sample.
  • Clean the pipette regularly.

Sample-to-pipette

Samples or aerosols from samples can enter the cone of the pipette.

Prevention:

  • Keep the pipette vertical when pipetting in order to prevent liquid from running into the pipette body.
  • Release the push button slowly.
  • To avoid aerosol contamination, use filter tips or use a positive displacement pipette and tips.

Sample-to-sample (carry-over)

The remains of a sample can mix with the next sample inside the tip and may cause a false test result.

Prevention:

  • Change the tip after each sample.
  • If you suspect your pipette is contaminated, clean with a suitable method, and autoclave if needed.

Navigate this guide:

Liquid handling
Proper pipetting techniques
Ergonomics
Maintenance & service