SEROLOGICAL PIPETTING

Serological pipettes are long, graduated plastic or glass pipettes used to move larger volumes, usually 1 mL to 50 mL. They are attached to a motorised pipette aid (pipette controller/ gun) that draws liquid up and lets it out.

WHAT YOU NEED

• Pipette aid (pipette controller)

• Sterile serological pipettes (5, 10 or 25 mL)

• The liquid to transfer and a receiving container

STEPS

1. Choose a pipette slightly larger than the volume you need.

2. Open the wrapper at the top end only, and push the pipette firmly into the pipette aid without touching the tip.

3. Remove the wrapper and keep the tip away from all surfaces.

4. Dip the tip into the liquid and press the top button to draw liquid slightly above your target mark.

5. Hold the pipette upright and read the bottom of the meniscus at eye level.

6. Use the bottom button to let liquid out slowly until the meniscus sits on the mark.

7. Move the pipette to the receiving container and dispense.

8. Discard the used pipette into the waste.

TIPS

• Never draw liquid up into the pipette aid itself; if it happens, replace the filter.

• Use a fresh sterile pipette each time you go back into a sterile stock.

• Keep the pipette vertical while reading volumes.