Laboratory Equipment: Pipettor

Automatic Pipettors - Introduction
The invention of automatic pipettors with disposable tips was a great boon to laboratory scientists, making it easy to deliver liquids, especially small volumes, accurately and precisely. Since automatic pipettors are precision instruments, they must be handled with respect, and obtaining good results with an automatic pipettor requires consistent technique. The pipettes we are using are piston-stroke pipettes that operate according to the air-cushion theory. Detailed instructions for use of the Rainin pipettor are online at

Automatic Pipettors - Instructions
Following is a quick overview of the use of the instrument.

  1. Be sure that you have the correct pipettor and tip for the volume you wish to transfer. Use the P200 with a yellow tip for 50 - 200 ml and a P1000 with a blue tip for 100 - 1,000 ml.

  2. Adjust the volume by turning the adjustment knob counterclockwise slightly above the desired setting, then by slowly turning the knob clockwise down to the desired volume. See Pipette Parts to display where this dial is on the pipette.

  3. Place the tip firmly on the pipettor.

  4. Push the plunger with your thumb until you first feel resistance (first stop). See Pipette Parts to display where this plunger is on the pipette.
  1. Hold the pipettor within 20 degrees of vertical with the end of the tip 2 mm under the surface of the liquid and slowly release your thumb to draw liquid into the tip.

  2. Place the tip so that its end touches the side of the receiving container and slowly press the plunger to the first stop. Wait two seconds then press the plunger to the final stop.
Hold the pipettor within 20 degrees of vertical

diffrent types of pipettor - Laboratory Equipment: Pipettor


On to Laboratory Equipment: Pipettor Calibration and Care