Choosing the Right Pipette for Your Application

Consider the physical properties of your sample

Today, there is a pipette for virtually every requirement … aqueous solutions, dense, viscous, or radioactive compounds, DNA sequencing, distributing aliquots, filling microtiter plates, etc.

The type of analysis you are performing, the physical properties of the liquid, and the volume range required will determine which pipette and tip you should use.

  Radioactive Samples Corrosive Samples Viscous
DNA, RNA & Biological Samples


Air-displacement pipettes are recommended for aqueous samples and for general laboratory work.
  • These always have a cushion of air (dead volume) between the pipette piston and the liquid sample.
  • The piston is a permanent part of the pipette


How do air-displacement pipettes work?

When the push-button is pressed on an air-displacement pipette, the piston inside the instrument moves down to let air out. Air is displaced by the piston. The volume of air displaced is equivalent to the volume of liquid aspirated.


Anachem Offers the Following Air Displacement Pipettes:

In addition a wide range of Multichannel Pipettes Provide Increased Productivity when working with multiple samples in Microplates.


Positive-displacement pipettes are recommended for problem samples (viscous, dense, volatile, radioactive, corrosive)
  • Direct contact of the piston with the sample (no air cushion)
  • Disposable piston (not a permanent part of the pipette)


Positive-displacement pipettes work like a syringe. There is no air cushion between the disposable piston and the sample. With no elastic air cushion to expand or contract, the aspiration force remains constant, unaffected by the physical properties of the sample.
This enables accurate pipetting of very viscous or high density samples, such as mercury or toothpaste.

Where elimination of potential cross contamination between samples is essential eg. forensic or diagnostic assays, positive displacement pipetting is advised.


Anachem's range of Repeater Pipettes also offer the advantages of positive displacement pipetting, plus the ability to multidispense sample aliquots, saving time and effort.

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