Using Serological Pipettes

Introduction

• Serological Pipettes: Graduated pipettes used to measure volumes over 1 ml.
• Two Scales: One for filling and another for dispensing.
• Cotton Plug: Prevents contaminants from entering the vacuum source.

Types of Pipette Pumps

Serological pipettes are used with three main types of pipette pumps:

1. Tri-Valve Pump

• Components:
  • A (Air) Valve: Releases air from the bulb.
  • S (Suction) Valve: Fills the pipette.
  • E (Exhaust) Valve: Empties remaining liquid.
• Usage:
  • Attach the pipette by twisting it into the bulb.
  • Squeeze the bulb to release air via the air valve.
  • Place pipette tip in the solution.
  • Press the S valve to fill above the desired volume.
  • Adjust the meniscus to the desired line using the E valve.
  • Transfer to the target container and dispense using the E valve.
  • Blow out any remaining liquid by holding the S valve and squeezing the bulb.

2. Syringe Style Pipette Pump

• Components:
  • Gasket: Attaches to the pipette.
  • Exhaust Valve: Expels solution.
  • Dial: Adjusts the amount transferred.
  • Plunger: Blows out remaining solution.
• Usage:
  • Insert pipette into the gasket by pressing and twisting.
  • Place in solution, roll dial to suck up liquid.
  • Adjust volume using dial.
  • Move to target container and press exhaust valve.
  • Blow out remaining solution with plunger.

3. Electronic Pipette Pump

• Components:
  • Gasket: Connects to the pipette.
  • Filter: Prevents contaminants.
  • Suction Button: Draws liquid.
  • Exhaust Button: Dispenses liquid.
• Usage:
  • Attach pipette by pushing and twisting into gasket.
  • Place tip in solution.
  • Press suction button to fill to desired volume.
  • Adjust volume with suction and exhaust buttons.
  • Transfer to container and dispense with exhaust button.